A5089031761- Advanced Fiber Optic Sensors
- Photonic and Optical Devices
- Seismic Imaging and Inversion Techniques
- Semiconductor Lasers and Optical Devices
- Analytical Chemistry and Sensors
- Seismic Waves and Analysis
- Railway Engineering and Dynamics
- Mechanical and Optical Resonators
- Particle Dynamics in Fluid Flows
- Quantum Information and Cryptography
- Fuzzy Logic and Control Systems
- Nuclear reactor physics and engineering
- Nuclear Engineering Thermal-Hydraulics
- Advanced Fiber Laser Technologies
- Railway Systems and Energy Efficiency
- Geophysics and Sensor Technology
- Quantum optics and atomic interactions
- Marine Biology and Environmental Chemistry
- Structural Health Monitoring Techniques
- Fluid Dynamics and Turbulent Flows
- Multilevel Inverters and Converters
- Molecular Sensors and Ion Detection
- Advanced DC-DC Converters
- Fluid Dynamics and Vibration Analysis
- Oceanographic and Atmospheric Processes
NORCE Norwegian Research Centre
2019-2025
Norwegian University of Science and Technology
2020-2023
Shell (United Kingdom)
2021
Chr. Michelsen Institute
2013-2018
University of Warwick
2000-2018
National Physical Laboratory
2007-2011
University of St Andrews
2009-2011
Central Queensland University
2003-2008
Ergon Energy (Australia)
2007
University of Waikato
1990
Measurement and monitoring of pH are essential in both the industry academia. It is therefore important to continue developing novel, low-cost sensors that provide increased accuracy over long periods time. Particularly promising based on materials show pH-dependent fluorescence intensity (FI) lifetime (FL). Carbon dots (CDs) emerging as candidates because their low cost, ease manufacturing, toxicity, negligible photobleaching. However, little has been done quantify FI FL values CDs. Here we...
Brillouin scattering in single-mode optical fibers has been investigated both theoretically and experimentally for a 180\ifmmode^\circ\else\textdegree\fi{} geometry 90\ifmmode^\circ\else\textdegree\fi{} angle. The acoustic normal modes were derived numerically evaluated cylindrical step-index fiber with an infinite finite cladding. It was found that the phonon population which contributes to back-scattering spectrum is narrower range shifted frequency when compared corresponding case bulk...
Fibre-optic sensing (FOS) techniques have gained notoriety for geoscientific and industrial applications over the past years. While most research tends to focus on spatially distributed (e.g. Distributed Acoustic/Vibration Sensing), here we investigate use of State Polarization (SoP) ocean observation. SoP is a technique that samples spatially-integrated measurements remotely, i.e. net change in polarization light between ends an optical fibre link up hundreds kilometers long, which can be...
The candela, the SI (système internationale) unit for optical radiation, has been one of base units since inception system. latest definition was in 1979, when it linked to derived unit, watt. Advances technology and needs communication sector suggest that is timely consideration be given redefining candela terms fundamental quantum entities, i.e. photons. Validation this approach will require comparison against most accurate conventional technique, cryogenic radiometry. A photon number...
Background: Most studies of the rapid response team (RRT) investigate effect introducing an RRT on outcomes all hospitalised patients. Less information exists patient epidemiology, or changes in call numbers with time.Objectives: To estimate inhospital mortality patients subject to review, proportion deaths reviewed by RRT, and annual time.Method: Retrospective observational study adult RRTequipped Australian hospitals for up 10 years (2000–2009).Participants outcome measures: Thirty-four...
This article reports the performance of an improved, newly developed, compact, low power, lifetime‐based optical sensor (optode) for measuring partial pressure dissolved CO 2 gas (pCO ) in natural waters. The results suggest that after preconditioning, these sensors are stable water time periods longer than 7 months. wide dynamic range about 0‐50000 µatm opens possibilities numerous applications which some presented. In normal marine environments with pCO levels 200‐1000 µatm, best‐obtained...
Phase-sensitive optical time domain reflectometry (ΦOTDR) is an important tool for distributed fiber sensing. In order to optimize system performance, the influence on sensing performance of factors such as laser frequency drift and variations in ambient conditions need be understood. While theoretical models can facilitate understanding, best our knowledge there only one numerical model ΦOTDR dynamic sensing, focusing particular detection scheme. this article we propose a simple generic...
The phase errors resulting from in-phase/quadrature (I/Q) demodulation in phase-sensitive optical time-domain reflectometry (φOTDR) are investigated theoretically, numerically, and experimentally for two recovery schemes: one employing Kramers-Kronig (KK)-based coherent detection, a second based on direct-detection scheme using an imbalanced Mach- Zehnder interferometer, 3 × coupler photodetectors. Mathematical models the estimation of differential variance proposed validated these schemes....
This paper presents a fuzzy control system to regulate the traffic flow approaching single real intersection which consists of multiple lanes with turns, by adjusting time parameters and phases signals. The are cataloged into several groups controlled individual lights. These lights further arranged light phases. A controller was developed length each phase. Evolutionary algorithms were employed generate logic rule base, using statistical data for intersection. To simulate car flows, new...
Five single crystals of parahydrogen were grown near the triple point, and their Brillouin spectra examined in known crystal directions. An analysis measured frequency shifts longitudinal transverse components led to direct determination adiabatic elastic constants at 13.2 K: C 11 = 3.34 ± 0.05, 13 0.56 0.03, 33 4.08 0.06, 44 1.04 0.03 kbar. The fifth constant 12 1.30 0.05 kbar was evaluated from relation + . Values following calculated: anisotropy, A 1.02 bulk modulus, B s 1.73 0.04 kbar,...
Surfaces that stay clean when immersed in water are important for an enormous range of applications from ships and buildings to marine, medical, other equipment. Up until now the main strategy designing self-cleaning surfaces has been combine hydrophilic/hydrophobic coatings with a high aspect ratio structuring (typically micron scale pillars) trap (semi)static water/air layer drag adhesion reduction. However, such coating can distort optical properties get damaged harsh environments,...
A flexible weight sensor based on optical fibre macrobending loss, using 1550 nm wavelength light and small bending path lengths is presented. An applied load depresses an impactor layer of cylindrical protrusions into a soft mat covered with fibre, causing the loss to increase. experimental study two types, materials, designs range protrusion bend radii from 3 mm 10 shown. For weights greater than 2 kg, linear response in (dB) observed for kg. The proportionality constant between load, thus...
In this paper we introduce Distributed Acoustic Sensing (DAS) and discuss its potential application in Intelligent Transportation Systems (ITS). We present the fundamentals of technology data processing methods required for converting raw into information that can be used to track position vehicles along a road real time. results experiments explore dependency defined DAS signal quality metrics as function vehicle speed, size distance from fiber, well how cables are installed. The indicate...
Experimental and theoretical results are presented for the Brillouin spectrum of single-mode optical fibers in 180° scattering geometry. It is shown that core diameters less than 10 μm both frequency shift spontaneous linewidth influenced by nature normal acoustic-mode wave-vector nonconservation acousto-optic interaction. The velocity lifetime longitudinal phonon excitations evaluated, consequences to stimulated assessed.
Ocean acidification has become a major climate change concern requiring continuous observation. Additionally, in the industry, pH surveillance is of great importance. Consequently, there pressing demand to develop robust and inexpensive sensors. Ratiometric fluorescence sensing stands out as promising concept. The application carbon dots fluorescent presents compelling avenue for advancement pH-sensing solutions. This potential underpinned by affordability dots, their straightforward...
Get PDF Email Share with Facebook Tweet This Post on reddit LinkedIn Add to CiteULike Mendeley BibSonomy Citation Copy Text P. J. Thomas, H. M. van Driei, and G. I. A. Stegeman, "Possibility of using an optical fiber Brillouin ring laser for inertial sensing," Appl. Opt. 19, 1906-1908 (1980) Export BibTex Endnote (RIS) HTML Plain alert Save article