Jiri Hromadka
University of Nottingham
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Publication
Featured researches published by Jiri Hromadka.
optical fiber sensors conference | 2017
Jiri Hromadka; Sergiy Korposh; Matthew Partridge; Stephen W. James; Frank Davis; Derrick Crump; Seung-Woo Lee; Ralph P. Tatam
An array of three long period gratings (LPGs) fabricated in a single optical fibre and multiplexed in the wavelength domain was used to measure simultaneously temperature, relative humidity (RH) and volatile organic compounds (VOCs). Each LPG sensor was designed to optimize its response to a desired measurand. The LPGs were fabricated with periods such that they operated at or near the phase matching turning point. The sensors were calibrated in the laboratory and the simultaneous measurement of the key indoor air quality parameters was undertaken in laboratory and office environments. It was demonstrated successfully that the data produced by the LPG sensor array under real conditions was in a good agreement with that produced by commercially available sensors. Further, the potential application of fibre optic sensors for VOCs detection at high levels has been demonstrated.
Sensors | 2017
Jiri Hromadka; Sergiy Korposh; Matthew Partridge; Stephen W. James; Frank Davis; Derrick Crump; Ralph P. Tatam
A long period grating (LPG) modified with a mesoporous film infused with a calixarene as a functional compound was employed for the detection of individual volatile organic compounds (VOCs) and their mixtures. The mesoporous film consisted of an inorganic part, SiO2 nanoparticles (NPs), along with an organic moiety of poly(allylamine hydrochloride) polycation PAH, which was finally infused with the functional compound, p-sulphanato calix[4]arene (CA[4]) or p-sulphanato calix[8]arene (CA[8]). The LPG sensor was designed to operate at the phase matching turning point to provide the highest sensitivity. The sensing mechanism is based on the measurement of the refractive index (RI) change induced by a complex of the VOCs with calixarene. The LPG, modified with a coating of 5 cycles of (SiO2 NPs/PAH) and infused with CA[4] or CA[8], was exposed to chloroform, benzene, toluene and acetone vapours. The British Standards test of the VOCs emissions from material (BS EN ISO 16000-9:2006) was used to test the LPG sensor performance.
Sixth European Workshop on Optical Fibre Sensors (EWOFS'2016) | 2016
Jiri Hromadka; Ricardo Correia; Sergiy Korposh
A fast method for the fabrication of the long period gratings (LPG) optical fibres operating at or near the phase matching turning point (PMTP) with the period of 109.0, 109.5 and 110.0 μm based on an amplitude mask writing system is described. The proposed system allows fabricating 3 cm long LPG sensors operating at PMPT within 20 min that is approximately 8 times faster than point-by-point approach. The reproducibility of the fabrication process was thoroughly studied. The response of the fabricated LPGs to the external change of the refractive index was investigated using water and methanol.
International Conference on Optical Fibre Sensors (OFS24) | 2015
Jiri Hromadka; Stephen W. James; Frank Davis; Ralph P. Tatam; Derrick Crump; Sergiy Korposh
An optical fibre long period grating (LPG) modified with a mesoporous film infused with a calixarene as a functional compound was employed for the detection of a mixture of volatile organic compounds (VOCs). The sensing mechanism is based on the transduction of the refractive index change induced by the complexion of the VOCs with calixarene into a change in the form of the transmission spectrum of the LPG. An LPG, modified with a calixarene-infused coating comprising 5 cycles of silica nanoparticles/poly(allylamine hydrochloride) polycation (SiO2/PAH), was exposed to mixture of VOCs emitted from paint at conditions simulating ISO standards test (16000-10).
International Conference on Biophotonics V | 2017
F. U. Hernandez; Tao Wang; Sergiy Korposh; Ricardo Correia; Barrie Hayes-Gill; Jiri Hromadka; N. N. Mohd Hazlan; A. Norris; D. Evans; Seung-Woo Lee; Stephen P. Morgan
Optical fibre sensing is a platform technology for applications in biomedical and environmental monitoring. Fibre Bragg Gratings can be used to monitor parameters such as pressure and temperature. Alternatively, coating the fibres with functional layers, either at the tip of the fibre, on a U-shaped fibre, or a long period grating enables sensing of analytes in liquids and gases. This paper describes the application of optical fibre sensing techniques during mechanical ventilation via an endotracheal tube in critical care. Functional coatings on the fibres are used to monitor humidity of inspired air and can be used to monitor other analytes.
optical fiber sensors conference | 2017
Jiri Hromadka; Begum Tokay; Stephen W. James; Sergiy Korposh
An optical fibre long period grating (LPG) modified with a thin film of HKUST-1, a material from metal organic framework (MOF) family, was employed for the detection of carbon dioxide. The sensing mechanism is based on the measurement of the change of the refractive index (RI) of the coating that is induced by the penetration of CO2 molecules into the HKUST-1 pores. The responses of the resonance bands in the transmission spectrum of an LPG modified with 40 layers of HKUST-1 upon exposure to carbon dioxide in mixture with nitrogen were investigated.
International Conference on Optical Fibre Sensors (OFS24) | 2015
Jiri Hromadka; Begum Tokay; Sergiy Korposh; Stephen W. James; Ralph P. Tatam
An optical fibre long period grating (LPG) modified with a thin film of ZIF-8, a zeolitic immidazol framework (ZIF) material, a subgroup of the metal organic framework (MOF) family, was employed for the detection of organic vapours. ZIF-8 film was deposited onto the surface of the LPG using an in-situ crystallization technique. The sensing mechanism is based on the measurement of the refractive index (RI) change induced by the penetration of the chemical molecules into the ZIF-8 pores. An LPG modified with 5 growth cycles of ZIF-8 responded to exposure to methanol and ethanol vapours.
Sensors and Actuators B-chemical | 2015
Jiri Hromadka; Begum Tokay; Stephen W. James; Ralph P. Tatam; Sergiy Korposh
Sensors and Actuators B-chemical | 2018
Jiri Hromadka; Begum Tokay; Ricardo Correia; Stephen P. Morgan; Sergiy Korposh
Sensors and Actuators B-chemical | 2018
Jiri Hromadka; Begum Tokay; Ricardo Correia; Stephen P. Morgan; Sergiy Korposh