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Full-Text Articles in Physics

Disaggregating Longer-Term Trends From Seasonal Variations In Measured Pv System Performance, Chibuisi Chinasaokwu Okorieimoh, Brian Norton, Michael Conlon Jan 2024

Disaggregating Longer-Term Trends From Seasonal Variations In Measured Pv System Performance, Chibuisi Chinasaokwu Okorieimoh, Brian Norton, Michael Conlon

Articles

Photovoltaic (PV) systems are widely adopted for renewable energy generation, but their performance is influenced by complex interactions between longer-term trends and seasonal variations. This study aims to remove these factors and provide valuable insights for optimising PV system operation. We employ comprehensive datasets of measured PV system performance over five years, focusing on identifying the distinct contributions of longer-term trends and seasonal effects. To achieve this, we develop a novel analytical framework that combines time series and statistical analytical techniques. By applying this framework to the extensive performance data, we successfully break down the overall PV system output into …


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.


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 …


Strain-Induced Spectral Tuning Of The Whispering Gallery Modes In A Cylindrical Micro-Resonator Formed By A Polymer Optical Fiber, Vishnu Kavungal, Arun Mallik, Gerald Farrell, Qiang Wu, Yuliya Semenova Feb 2017

Strain-Induced Spectral Tuning Of The Whispering Gallery Modes In A Cylindrical Micro-Resonator Formed By A Polymer Optical Fiber, Vishnu Kavungal, Arun Mallik, Gerald Farrell, Qiang Wu, Yuliya Semenova

Articles

A mechanical strain assisted technique for spectral tuning of whispering gallery modes (WGM) in a cylindrical micro-resonator formed by a polymer optical fiber (POF) is investigated. WGMs in the POF based micro-cylinder are excited by evanescent light coupling using a tapered single mode silica fiber. WGMs observed in the transmission spectrum of the silica fiber taper have a high extinction ratio of up to 19 dB and a Q-factor of up to 2.64 × 104. The application of tensile axial strain (μɛ) in the range from 0 to 1746 μɛ (0.17 %) to the POF micro-resonator results in …


Strengthening The Development Of The Short-Rotation Plantations Bioenergy Sector: Policy Insights From Six European Countries, Carlos Parra-Lopez, Martin Holley, Kevin Lindegaard, Samir Sayadi, Gonzalo Esteban-Lopez, Victor Duran-Zuazo, Christoph Knauer, Hans-Georg Von Engelbrechten, Ralf Winterber, Annika Henriksson, Annette Lamley, Anders Nylander, Susanne Paulrud, Pauline Leonard, Patrick Daly, Lukasz Drzewaszewski, Wojciech Rzewuski Jan 2017

Strengthening The Development Of The Short-Rotation Plantations Bioenergy Sector: Policy Insights From Six European Countries, Carlos Parra-Lopez, Martin Holley, Kevin Lindegaard, Samir Sayadi, Gonzalo Esteban-Lopez, Victor Duran-Zuazo, Christoph Knauer, Hans-Georg Von Engelbrechten, Ralf Winterber, Annika Henriksson, Annette Lamley, Anders Nylander, Susanne Paulrud, Pauline Leonard, Patrick Daly, Lukasz Drzewaszewski, Wojciech Rzewuski

Articles

This paper, based on a participatory methodological framework involving expert stakeholders and researchers from six European countries (Germany, Ireland, Poland, Spain, Sweden and UK), analyses the priority issues for the development of short-rotation plantations (SRP), and proposes a series of policy strategies to strengthen this development. The results indicate that there is a lack of awareness of the multifaceted benefits of SRP at the level of farmers, policy makers and public authorities. More research is required to put a value on the multifunctionality of SRP and justify its public support. Small-scale projects using established technologies are also required with energy …


The Evaluation And Implementation Of Magnetic Fields For Large Strain Uniaxial And Biaxial Cyclic Testing Of Magnetorheological Elastomers., Dave Gorman, Niall Murphy, Ray Ekins, Stephen Jerrams May 2016

The Evaluation And Implementation Of Magnetic Fields For Large Strain Uniaxial And Biaxial Cyclic Testing Of Magnetorheological Elastomers., Dave Gorman, Niall Murphy, Ray Ekins, Stephen Jerrams

Articles

Magnetorheological Elastomers (MREs) are “smart” materials whose physical properties are altered by the application of magnetic fields. In previous studies the properties of MREs have been evaluated under a variety of conditions, however little attention has been paid to the recording and reporting of the magnetic fields used in these tests [1]. Currently there is no standard accepted method for specifying the magnetic field applied during MRE testing. This study presents a detailed map of a magnetic field applied during MRE tests as well as providing the first comparative results for uniaxial and biaxial testing under high strain fatigue test …


Hysteresis And Anchoring Energy In Ferroelectric Liquid Crystals, Yuri Panarin Jan 1993

Hysteresis And Anchoring Energy In Ferroelectric Liquid Crystals, Yuri Panarin

Articles

The frequency dispersion of the coercive force of Ferroelectric Liquid Crystals (FLC) cells has been detected and examined in the range of infralow (lower than 0.1 Hz) frequencies. To clarify the low-frequency dispersion, the model has been suggested, based on the arrangement of free charges and well describing the experimental curves. The method for determination of the energy of FLC anchoring at the surface, developed on the basis of the static hysteresis loop, has been proposed. The dependence of bistability and the anchoring energy upon the orientant layer thickness has experimentally been investigated.