Article
Engineering, Electrical & Electronic
Teng Zhang, Zhenyang Ding, Kun Liu, Haohan Guo, Peidong Hua, Sheng Li, Ming Pan, Ji Liu, Junfeng Jiang, Tiegen Liu
Summary: We demonstrate a short-time long distance distributed high-temperature sensing by non-local Haar transform (NLH) in optical frequency domain reflectometry (OFDR). With the proposed NLH method, we achieved a short-time distributed high-temperature sensing ranging from 950 degrees C to 1050 degrees C over 102 m by reduced-cladding single mode fiber (RC-SMF) with a sensing spatial resolution of 2 cm. The NLH method has a best performance to restore the consistency of spectral shift distribution caused by the same temperature change without deterioration of sensing spatial resolution compared with traditional image denoising methods.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Sina Sedighi, Marcelo A. Soto, Alin Jderu, Dorel Dorobantu, Marius Enachescu, Dominik Ziegler
Summary: Distributed chemical sensing is achieved using standard acrylate coated optical fibers, where swelling of the coating induces strain in the fiber's silica core. This concept has been validated by measuring strain responses of various aqueous and organic solvents. Thermal effects can be discriminated from strain using uncoated fiber segments, leading to more accurate strain readings.
Article
Engineering, Mechanical
Sergei Mikhailov, Jeroen van Wittenberghe, Geert Luyckx, Philippe Thibaux, Thomas Geernaert, Francis Berghmans
Summary: In this study, we demonstrated the application of distributed fiber optic strain sensing based on optical frequency-domain reflectometry for early detection and location of fatigue cracks in welds in steel tubular test specimens. By subjecting the specimens to resonant bending load and continuously measuring the strain distributions with high resolution, we successfully detected and located fatigue cracks originating from the inner surface of the specimens in real time. The detection of crack initiation may provide relevant information for estimating the remaining lifetime of the component.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Biophysics
Peidong Hua, Zhenyang Ding, Kun Liu, Haohan Guo, Ming Pan, Teng Zhang, Sheng Li, Junfeng Jiang, Tiegen Liu
Summary: A distributed optical fiber biosensor based on tapered fiber and optical frequency domain reflectometry (OFDR) is proposed in this paper. By measuring the shift of the local Rayleigh backscattering spectra (RBS) caused by the refractive index (RI) change of the external medium surrounding the tapered fiber using OFDR, the concentration change of anti-human IgG can be located. This distributed sensor has the potential to achieve micron-level localization of biochemical substances such as cancer cells.
BIOSENSORS & BIOELECTRONICS
(2023)
Article
Chemistry, Analytical
Andres Biondi, Rui Wu, Lidan Cao, Balaji Gopalan, Jackson Ivey, Camila Garces, Michael Mitchell, John D. D. Williams, Xingwei Wang
Summary: This paper introduces a distributed fiber optic smart textile (DFOST) embedded into a composite panel for optimizing the performance and durability of composite materials. DFOST is created using an embroidery method, allowing for different layout patterns and enabling two- or three-dimensional measurements. Measurements of strain, temperature, and displacement changes are obtained using optical frequency domain reflectometry (OFDR).
Article
Chemistry, Analytical
Ziyi Lu, Ting Feng, Fang Li, Xiaotian Steve Yao
Summary: An innovative distributed temperature sensing method using optical frequency-domain reflectometry (OFDR) and Rayleigh backscattering enhanced fiber (RBEF) is proposed. The method accurately demodulates temperature variation by analyzing the position shift of high backscattering points along the RBEF. Experimental results show a linear relationship between temperature variation and the total position displacement of high backscattering points. The temperature sensing resolution is determined by the distribution of high backscattering points and the spatial resolution of the OFDR system.
Article
Optics
Andrea Baggio, Matteo Turani, Massimo Olivero, Milena Salvo, Diego Pugliese, Marco Sangermano
Summary: A new system is developed to detect hydrocarbons using optical fiber distributed sensing. The system utilizes a custom-designed optical fiber with silica core and thin silicone cladding, providing quick and selective absorption of oil products and insensitivity to water. By detecting Rayleigh backscattering, the system demonstrates a rapid response to high refractive index hydrocarbons, with a response time of approximately 1 s. Furthermore, in its high-resolution version, the system can accurately locate leakages with an accuracy of 14 cm.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Huajian Zhong, Cailing Fu, Lijie Wang, Bin Du, Pengfei Li, Yanjie Meng, Lin Chen, Chao Du, Yiping Wang
Summary: This study proposes a high-spatial-resolution optical frequency domain reflectometry method with a single interferometer, using a self-compensation technique to successfully eliminate phase noise and obtain a compensated signal with high signal-to-noise ratio. The high spatial resolution is achieved by analyzing the length of the delay fiber at different measurement distances. This method has great potential in the field of distributed measurement.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Optics
Tuo Lv, Ruming Wei, Da-Peng Zhou, Wei Peng, Liang Chen, Xiaoyi Bao
Summary: In this Letter, the authors propose a method for fully distributed strain sensing of multiple optical fibers using optical frequency-domain reflectometry. By utilizing the unique Rayleigh backscattering pattern of each fiber as a key signature, simultaneous measurement along multiple fibers can be achieved even when individual patterns are buried in the signals from all the fibers. Preliminary results demonstrate the feasibility of demodulating four single-mode fibers simultaneously, with the potential to extend to six, providing high spatial resolutions of the order of millimeters. This approach offers great simplicity and cost reduction for fully distributed strain sensing in multiple optical fibers or multiple cores in a specialty fiber.
Article
Engineering, Electrical & Electronic
Ming Pan, Peidong Hua, Zhenyang Ding, Dongfang Zhu, Kun Liu, Junfeng Jiang, Chenhuan Wang, Haohan Guo, Teng Zhang, Sheng Li, Tiegen Liu
Summary: In this paper, a method for long distance distributed strain sensing in optical frequency domain reflectometry (OFDR) is presented, which uses image processing for denoising to enhance the performance of distributed sensing. The proposed method, BM3D-SAPCA, searches for similar 2D image blocks in 3D arrays and takes advantage of the high level of similitude and redundancy in the multidimensional information to denoise. Experimental results show that the BM3D-SAPCA method effectively suppresses noise and achieves a spatial resolution of 5 cm and strain resolution of 2 mu epsilon in distributed strain sensing.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Chemistry, Analytical
Guolu Yin, Pengxi Yang, Hu Xiao, Yu Wang, Zeheng Zhang, Fabing Yan, Tao Zhu
Summary: A distributed liquid-level sensor based on optical frequency domain reflectometry and no-core fiber is proposed in this study. The experimental results show that the method can achieve high resolution, good stability, large measurement range, and high signal-to-noise ratio, making it suitable for intelligent industry and extreme environments.
Article
Radiology, Nuclear Medicine & Medical Imaging
Mischa Megens, Merel D. Leistikow, Anneke van Dusschoten, Martin B. van der Mark, Jeroen J. L. Horikx, Elbert G. van Putten, Gert W. 't Hooft
Summary: The FORS technology accurately visualizes the shape of medical devices in three dimensions, providing guidance and navigation during minimally invasive procedures. Bench experiments demonstrated submillimeter accuracy in tip location and milliradian accuracy in orientation. The technology surpasses other navigation and tracking technologies in precision, potentially reducing the need for fluoroscopy during procedures.
Article
Engineering, Electrical & Electronic
Tatsuya Okamoto, Daisuke Iida, Yusuke Koshikiya, Nazuki Honda
Summary: Distributed vibration sensing using optical fibers as strain sensors provides a new function for existing optical communication networks. The customized setup of optical frequency domain reflectometry enables the investigation of dynamic strain distribution along fibers deployed in varied conditions, with sub-1-m spatial resolution revealing the impact of deployment conditions on dynamic strain.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Haoyu Wang, Dan Zhang, Kang Ren, Bin Shi, Junyi Guo, Mengya Sun
Summary: This article develops a novel strain-sensitive water leakage sensing optical cable (SL cable) and proposes a new tunnel water leakage distributed monitoring method to overcome the shortcomings of existing methods. The effects of leakage rate, axial load, and layout angle of the SL cable are investigated through experiments, and the high sensitivity and reusability of the SL cable are verified. The results highlight the potential of this method for practical implementation in water leakage monitoring.
IEEE SENSORS JOURNAL
(2023)
Article
Optics
Zongda Zhu, Dexin Ba, Lu Liu, Liqiang Qiu, Shunhu Yang, Yongkang Dong
Summary: A novel temperature-compensated multi-point refractive index sensing system was proposed, combining cascaded FP sensors and FMCW interferometry. Experimental results showed high precision and sensitivity, making it suitable for practical applications requiring a large number of sensing points.
Article
Engineering, Electrical & Electronic
Pablo D. Hernandez, Jaime A. Ramirez, Marcelo A. Soto
Summary: This paper proposes deep learning models trained with real seismic data to detect earthquakes in fiber-optic distributed acoustic sensor (DAS) measurements. The models successfully extract relevant features of earthquakes from traditional broadband seismometer data. Despite intrinsic differences and labeling errors in DAS data, the models still achieve high accuracy.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Felipe Munoz, Marcelo A. Soto
Summary: In this study, a fully blind method based on near-field acoustic array processing is proposed, which can be used on any optical fibre positioning geometry with angular diversity. This method can monitor mechanical vibrations and enhance signal-to-noise ratio without the need for source and fibre location information in distributed acoustic sensors.
NATURE COMMUNICATIONS
(2022)
Article
Optics
Felipe Munoz, Loreto Romero, Marcelo A. Soto
Summary: This study proposes the use of phase cross correlation to estimate the frequency shift of the Rayleigh intensity spectral response in p-OTDR. The proposed approach is an amplitude-unbiased technique that evenly weights all spectral samples, reducing sensitivity to high-intensity Rayleigh spectral samples and minimizing estimation errors. Experimental results demonstrate that the proposed method significantly reduces large errors in frequency shift estimation, improving the reliability of distributed measurements while maintaining a low frequency uncertainty of approximately 1.0 MHz.
Article
Electrochemistry
P. M. V. Fernandes, O. Brincoveanu, A. Pantazi, A. Petica, C. M. Pereira, A. Fernando Silva, M. Enachescu, L. Anicai
Summary: The possible fabrication of porous anodic oxide films on aluminium in ionic liquids has been investigated in this study. The study found that the use of choline dihydrogen citrate eutectic mixtures with oxalic acid and isopropyl alcohol and ethylene glycol resulted in the production of compact and uniform anodic alumina layers. The size of the pores and the distance between them were influenced by the electrolyte type and anodisation conditions.
TRANSACTIONS OF THE INSTITUTE OF METAL FINISHING
(2023)
Article
Chemistry, Multidisciplinary
Calin Constantin Moise, Geanina Valentina Mihai, Liana Anicai, Eduard Monaico, Veaceslav V. Ursaki, Marius Enachescu, Ion M. Tiginyanu
Summary: Porous InP templates were prepared by anodic etching of InP substrates with different electrical conductivities using an environmentally friendly electrolyte. Ni nanoparticles were directly deposited into the templates by pulsed electroplating without additional intermediary layers. The technology is expected to have applications in sensing and photocatalysis, as well as exploring plasmonic and magnetic properties.
Article
Materials Science, Multidisciplinary
Stefania Costovici, Aida Pantazi, Danut Balan, Anca Cojocaru, Teodor Visan, Marius Enachescu, Liana Anicai
Summary: This study compares the electrodeposition of tin-reduced graphene oxide composite (Sn-rGO) to the electrodeposition of tin metal (Sn) from a deep eutectic solvent (DES). Experimental results show that GO is reduced during the tin electrodeposition and graphene related material is incorporated in the composite film. The presence of rGO in the deposit affects the preferred orientation of Sn growth. The deposition process of Sn-rGO composite is controlled by diffusion, with nucleation evolving from progressive to instantaneous with increasing overpotential. The corrosion performance and solderability characteristics of the composite coatings are slightly improved compared to pure Sn ones.
Article
Chemistry, Multidisciplinary
Sabrina State (Rosoiu), Laura-Bianca Enache, Pavel Potorac, Mariana Prodana, Marius Enachescu
Summary: Cu nanocolumnar structure electrodes were synthesized using a direct-current magnetron sputtering technique for glucose sensing. The electrodes showed good electrochemical affinity towards glucose and exhibited linear response up to 2 mM concentration. They also demonstrated resistance to interference from other substances at physiological concentrations.
Article
Optics
Xizi Sun, Zhisheng Yang, Xiaobin Hong, Simeng Jin, Jie Luo, Marcelo A. Soto, Jian Wu
Summary: A Brillouin optical time-domain analysis (BOTDA) scheme based on hybrid amplification, consisting of a distributed Raman amplification and a lumped amplification provided by remotely pumped Erbium-doped fibers, is proposed. The scheme enables the longest sensing distance among existing repeaterless techniques. The optimization of optical powers, analysis of pulse distortion, and the use of compensating pulse approach are studied to achieve high-performance long-distance BOTDA sensors.
Article
Physics, Applied
Yosuke Mizuno, Naoki Motoishi, Kohei Noda, Antreas Theodosiou, Kyriacos Kalli, Heeyoung Lee, Kentaro Nakamura, Marcelo A. Soto
Summary: We show that fiber Bragg gratings in polymer optical fibers can generate reflection peaks in any wavelength range by exciting high-order propagation modes, thus improving the design of sensing systems for specific applications.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Physical
Ana T. S. C. Brandao, Renata Costa, Sabrina State, Pavel Potorac, Catarina Dias, Jose A. Vazquez, Jesus Valcarcel, A. Fernando Silva, Marius Enachescu, Carlos M. Pereira
Summary: Carbon materials derived from squid and prawn shells were used as electrodes for energy storage devices. The obtained porous carbons were characterized to determine their morphology, composition, and structure. Electrochemical characterization revealed the specific capacitance and performance of the chitin-based carbon materials. Preliminary studies were performed to understand the effect of different electrolytes on the capacitance and retention of the half-cell setup. This research provided insights into the potential application of chitin-based carbon materials in energy storage devices.
Article
Materials Science, Multidisciplinary
Oana Andreea Lazar, Anastas Savov Nikolov, Calin Constantin Moise, Geanina Valentina Mihai, Mariana Prodana, Marius Enachescu
Summary: In this study, pulsed laser ablation in aqueous isopropanol solution was used to produce platinum nanoparticles. The optical and morphological properties of the nanoparticles were investigated by varying the IPA concentration and ablation time. The nanoparticles showed spherical shape and their properties were characterized using UV/Vis transmission spectra and High-Resolution Scanning Transmission Electron Microscopy.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Mariana Prodana, Daniela Ionita, Andrei Bogdan Stoian, Ioana Demetrescu, Geanina Valentina Mihai, Marius Enachescu
Summary: The study focuses on a new alloy containing rare metals such as Ta and Zr with proven antibacterial properties. The aim is to develop multifunctional coatings on Ti-Zr-Ta-Ag alloy using chitosan, bioglass, and ZnO. Through various analyses, it is found that the coatings exhibit good stability, uniform distribution of components, and functional groups of BG, ZnO, and chitosan. The coated samples show promising characteristics for potential bioapplications.
Article
Chemistry, Analytical
Felipe Munoz, Javier Urricelqui, Marcelo A. Soto, Marco Jimenez-Rodriguez
Summary: Distributed acoustic sensors (DAS) use optical fibers to monitor vibrations at multiple locations. A correlation-based method is proposed to automatically find spatial monitoring locations with good temporal waveform repeatability, taking into account changes in coupling and acoustic interference. The results show high repeatability for measurements taken over three days, even with variations in fiber installation along the railway track.
Article
Chemistry, Multidisciplinary
Ana T. S. C. Brandao, Sabrina State, Renata Costa, Laura-Bianca Enache, Pavel Potorac, Jose A. Vazquez, Jesus Valcarcel, A. Fernando Silva, Marius Enachescu, Carlos M. M. Pereira
Summary: The scientific community is increasingly interested in developing sustainable carbon materials from biomass waste to reduce reliance on fossil fuels. In this study, blue shark chondroitin sulfate and gelatine were used as precursors to produce porous carbon materials for energy storage devices. The carbon materials derived from blue shark showed a higher specific surface area and capacitance.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Multidisciplinary
Gui Li, Artem Iakunkov, Nicolas Boulanger, Oana Andreea Lazar, Marius Enachescu, Alejandro Grimm, Alexandr V. Talyzin
Summary: In this study, activated carbons were produced from pine cones, spruce cones, larch cones, and a pine bark/wood chip mixture to investigate the influence of the precursor on the properties of the final materials. The activated carbons produced from different precursors showed similar specific surface area, pore size distribution, and performance in supercapacitor electrodes. The results suggest that the type of precursor has less importance compared to the carbonization and activation process in producing high surface area activated carbons.