[{"article_number":"17","external_id":{"isi":["000758547200001"]},"ddc":["620"],"title":"Electrically tunable lens (ETL) - based variable focus imaging system for parametric surface texture analysis of materials","type":"journal_article","issue":"1","department":[{"_id":"KiMo"}],"quality_controlled":"1","article_type":"original","date_updated":"2023-08-09T10:16:10Z","publication_identifier":{"eissn":["2072-666X"]},"oa_version":"Published Version","has_accepted_license":"1","volume":13,"month":"01","publication":"Micromachines","isi":1,"file_date_updated":"2022-01-03T13:43:01Z","language":[{"iso":"eng"}],"article_processing_charge":"Yes","day":"01","_id":"10584","scopus_import":"1","keyword":["surface texture","electrically tunable lens","materials","hypromellose","surface topography","surface roughness","pharmaceutical tablet","variable focus imaging"],"acknowledgement":"The authors acknowledge the financial assistance provided by the University of Huddersfield.","year":"2022","abstract":[{"lang":"eng","text":"Electrically tunable lenses (ETLs) are those with the ability to alter their optical power in response to an electric signal. This feature allows such systems to not only image the areas of interest but also obtain spatial depth perception (depth of field, DOF). The aim of the present study was to develop an ETL-based imaging system for quantitative surface analysis. Firstly, the system was calibrated to achieve high depth resolution, warranting the accurate measurement of the depth and to account for and correct any influences from external factors on the ETL. This was completed using the Tenengrad operator which effectively identified the plane of best focus as demonstrated by the linear relationship between the control current applied to the ETL and the height at which the optical system focuses. The system was then employed to measure amplitude, spatial, hybrid, and volume surface texture parameters of a model material (pharmaceutical dosage form) which were validated against the parameters obtained using a previously validated surface texture analysis technique, optical profilometry. There were no statistically significant differences between the surface texture parameters measured by the techniques, highlighting the potential application of ETL-based imaging systems as an easily adaptable and low-cost alternative surface texture analysis technique to conventional microscopy techniques"}],"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"author":[{"first_name":"Jorabar Singh","full_name":"Nirwan, Jorabar Singh","last_name":"Nirwan"},{"last_name":"Lou","full_name":"Lou, Shan","first_name":"Shan"},{"first_name":"Saqib","full_name":"Hussain, Saqib","last_name":"Hussain"},{"first_name":"Muhammad","id":"32c21954-2022-11eb-9d5f-af9f93c24e71","last_name":"Nauman","orcid":"0000-0002-2111-4846","full_name":"Nauman, Muhammad"},{"first_name":"Tariq","full_name":"Hussain, Tariq","last_name":"Hussain"},{"full_name":"Conway, Barbara R.","last_name":"Conway","first_name":"Barbara R."},{"full_name":"Ghori, Muhammad Usman","last_name":"Ghori","first_name":"Muhammad Usman"}],"intvolume":"        13","date_created":"2022-01-02T23:01:33Z","doi":"10.3390/mi13010017","publisher":"MDPI","user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","oa":1,"status":"public","citation":{"ama":"Nirwan JS, Lou S, Hussain S, et al. Electrically tunable lens (ETL) - based variable focus imaging system for parametric surface texture analysis of materials. <i>Micromachines</i>. 2022;13(1). doi:<a href=\"https://doi.org/10.3390/mi13010017\">10.3390/mi13010017</a>","short":"J.S. Nirwan, S. Lou, S. Hussain, M. Nauman, T. Hussain, B.R. Conway, M.U. Ghori, Micromachines 13 (2022).","apa":"Nirwan, J. S., Lou, S., Hussain, S., Nauman, M., Hussain, T., Conway, B. R., &#38; Ghori, M. U. (2022). Electrically tunable lens (ETL) - based variable focus imaging system for parametric surface texture analysis of materials. <i>Micromachines</i>. MDPI. <a href=\"https://doi.org/10.3390/mi13010017\">https://doi.org/10.3390/mi13010017</a>","ista":"Nirwan JS, Lou S, Hussain S, Nauman M, Hussain T, Conway BR, Ghori MU. 2022. Electrically tunable lens (ETL) - based variable focus imaging system for parametric surface texture analysis of materials. Micromachines. 13(1), 17.","mla":"Nirwan, Jorabar Singh, et al. “Electrically Tunable Lens (ETL) - Based Variable Focus Imaging System for Parametric Surface Texture Analysis of Materials.” <i>Micromachines</i>, vol. 13, no. 1, 17, MDPI, 2022, doi:<a href=\"https://doi.org/10.3390/mi13010017\">10.3390/mi13010017</a>.","ieee":"J. S. Nirwan <i>et al.</i>, “Electrically tunable lens (ETL) - based variable focus imaging system for parametric surface texture analysis of materials,” <i>Micromachines</i>, vol. 13, no. 1. MDPI, 2022.","chicago":"Nirwan, Jorabar Singh, Shan Lou, Saqib Hussain, Muhammad Nauman, Tariq Hussain, Barbara R. Conway, and Muhammad Usman Ghori. “Electrically Tunable Lens (ETL) - Based Variable Focus Imaging System for Parametric Surface Texture Analysis of Materials.” <i>Micromachines</i>. MDPI, 2022. <a href=\"https://doi.org/10.3390/mi13010017\">https://doi.org/10.3390/mi13010017</a>."},"file":[{"file_size":5370675,"file_name":"2021_Micromachines_Singh.pdf","date_updated":"2022-01-03T13:43:01Z","file_id":"10601","checksum":"5d062cae3f1acb251cacb21021724c4e","access_level":"open_access","relation":"main_file","content_type":"application/pdf","creator":"alisjak","success":1,"date_created":"2022-01-03T13:43:01Z"}],"publication_status":"published","date_published":"2022-01-01T00:00:00Z"},{"extern":"1","page":"37-50","abstract":[{"text":"The time that rainfall takes to reach the outlet of a catchment as discharge (transit time) is a fundamental and\r\nintegrated measure of catchment hydrological processes and solute transport mechanisms. As such, many efforts\r\nhave been dedicated to its understanding and quantification. However, defining and ranking which factors,\r\ninternal and external to the system, control the distributions of transit time is still an open challenge. Here, we\r\ndevelop a two-stage approach to explore climate and topography controls on transit time, using a fully distributed hydrological model coupled with a transport component. Specifically, we apply the model to two\r\nsynthetic topographies under five observed climate regimes. With this setup, water fluxes from two years of daily\r\nrainfall events are singularly tracked across the catchments to then derive the distributions of transit time and\r\nfraction of young water for each combination of topography and climate. Results highlight a considerable\r\nvariability of transit times in all climates and a pronounced effect of topography within a given climate. They\r\nfurther reveal that for wet climates it is possible to define a curve describing water transit time as a function of\r\ncumulative discharge that only depends on topographic properties. On the contrary, in dry climates the variability of transit time and young water fraction is much larger and not amenable to a simple summary. Despite\r\nsimplifications, quantitative model-based inferences of transit time distributions are useful to better understand\r\nhow climate and topography affect catchment functioning.","lang":"eng"}],"year":"2019","keyword":["Transit time distributions","Young water","Climate","Topography","Distributed hydrological modelling"],"scopus_import":"1","OA_type":"closed access","_id":"22549","day":"01","article_processing_charge":"No","date_published":"2019-02-01T00:00:00Z","citation":{"ieee":"F. Remondi, M. Botter, P. Burlando, and S. Fatichi, “Variability of transit time distributions with climate and topography: A modelling approach,” <i>Journal of Hydrology</i>, vol. 569. Elsevier, pp. 37–50, 2019.","chicago":"Remondi, Federica, Martina Botter, Paolo Burlando, and Simone Fatichi. “Variability of Transit Time Distributions with Climate and Topography: A Modelling Approach.” <i>Journal of Hydrology</i>. Elsevier, 2019. <a href=\"https://doi.org/10.1016/j.jhydrol.2018.11.011\">https://doi.org/10.1016/j.jhydrol.2018.11.011</a>.","ista":"Remondi F, Botter M, Burlando P, Fatichi S. 2019. Variability of transit time distributions with climate and topography: A modelling approach. Journal of Hydrology. 569, 37–50.","mla":"Remondi, Federica, et al. “Variability of Transit Time Distributions with Climate and Topography: A Modelling Approach.” <i>Journal of Hydrology</i>, vol. 569, Elsevier, 2019, pp. 37–50, doi:<a href=\"https://doi.org/10.1016/j.jhydrol.2018.11.011\">10.1016/j.jhydrol.2018.11.011</a>.","short":"F. Remondi, M. Botter, P. Burlando, S. Fatichi, Journal of Hydrology 569 (2019) 37–50.","apa":"Remondi, F., Botter, M., Burlando, P., &#38; Fatichi, S. (2019). Variability of transit time distributions with climate and topography: A modelling approach. <i>Journal of Hydrology</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.jhydrol.2018.11.011\">https://doi.org/10.1016/j.jhydrol.2018.11.011</a>","ama":"Remondi F, Botter M, Burlando P, Fatichi S. Variability of transit time distributions with climate and topography: A modelling approach. <i>Journal of Hydrology</i>. 2019;569:37-50. doi:<a href=\"https://doi.org/10.1016/j.jhydrol.2018.11.011\">10.1016/j.jhydrol.2018.11.011</a>"},"publication_status":"published","status":"public","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","publisher":"Elsevier","date_created":"2026-07-27T12:30:24Z","doi":"10.1016/j.jhydrol.2018.11.011","intvolume":"       569","author":[{"first_name":"Federica","full_name":"Remondi, Federica","last_name":"Remondi"},{"first_name":"Martina","full_name":"Botter, Martina","last_name":"Botter"},{"first_name":"Paolo","full_name":"Burlando, Paolo","last_name":"Burlando"},{"id":"cf8e546b-a9b0-11f0-a43b-aa89ed1b56d6","first_name":"Simone","last_name":"Fatichi","full_name":"Fatichi, Simone"}],"das_tickbox":"1","date_updated":"2026-08-06T08:12:57Z","article_type":"original","quality_controlled":"1","type":"journal_article","title":"Variability of transit time distributions with climate and topography: A modelling approach","language":[{"iso":"eng"}],"month":"02","publication":"Journal of Hydrology","volume":569,"oa_version":"None","publication_identifier":{"eissn":["1879-2707"],"issn":["0022-1694"]}},{"author":[{"full_name":"Roques-Carmes, Charles","last_name":"Roques-Carmes","first_name":"Charles","id":"e2e68fc9-6505-11ef-a541-eb4e72cc3e82"},{"full_name":"Bodin, N.","last_name":"Bodin","first_name":"N."},{"first_name":"G.","full_name":"Monteil, G.","last_name":"Monteil"},{"first_name":"J.F.","last_name":"Quiniou","full_name":"Quiniou, J.F."}],"intvolume":"       248","date_created":"2026-03-30T12:22:47Z","doi":"10.1016/s0043-1648(00)00562-7","publisher":"Elsevier","date_published":"2001-03-01T00:00:00Z","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","status":"public","citation":{"apa":"Roques-Carmes, C., Bodin, N., Monteil, G., &#38; Quiniou, J. F. (2001). Description of rough surfaces using conformal equivalent structure concept: Part 1. Stereological approach. <i>Wear</i>. Elsevier. <a href=\"https://doi.org/10.1016/s0043-1648(00)00562-7\">https://doi.org/10.1016/s0043-1648(00)00562-7</a>","short":"C. Roques-Carmes, N. Bodin, G. Monteil, J.F. Quiniou, Wear 248 (2001) 82–91.","ama":"Roques-Carmes C, Bodin N, Monteil G, Quiniou JF. Description of rough surfaces using conformal equivalent structure concept: Part 1. Stereological approach. <i>Wear</i>. 2001;248(1-2):82-91. doi:<a href=\"https://doi.org/10.1016/s0043-1648(00)00562-7\">10.1016/s0043-1648(00)00562-7</a>","chicago":"Roques-Carmes, Charles, N. Bodin, G. Monteil, and J.F. Quiniou. “Description of Rough Surfaces Using Conformal Equivalent Structure Concept: Part 1. Stereological Approach.” <i>Wear</i>. Elsevier, 2001. <a href=\"https://doi.org/10.1016/s0043-1648(00)00562-7\">https://doi.org/10.1016/s0043-1648(00)00562-7</a>.","ieee":"C. Roques-Carmes, N. Bodin, G. Monteil, and J. F. Quiniou, “Description of rough surfaces using conformal equivalent structure concept: Part 1. Stereological approach,” <i>Wear</i>, vol. 248, no. 1–2. Elsevier, pp. 82–91, 2001.","mla":"Roques-Carmes, Charles, et al. “Description of Rough Surfaces Using Conformal Equivalent Structure Concept: Part 1. Stereological Approach.” <i>Wear</i>, vol. 248, no. 1–2, Elsevier, 2001, pp. 82–91, doi:<a href=\"https://doi.org/10.1016/s0043-1648(00)00562-7\">10.1016/s0043-1648(00)00562-7</a>.","ista":"Roques-Carmes C, Bodin N, Monteil G, Quiniou JF. 2001. Description of rough surfaces using conformal equivalent structure concept: Part 1. Stereological approach. Wear. 248(1–2), 82–91."},"publication_status":"published","day":"01","article_processing_charge":"No","year":"2001","abstract":[{"lang":"eng","text":"The notion of elliptic or ellipsoidal conformal equivalent structure is introduced to model rough surface topography by use of convex homogenized shapes. The method is based on classical stereological results dealing with the relation between the number of intersections of an object with a set of parallel straight lines. The approach leads to an algorithm comparing the number of intercepts on both sampled surfaces and homogenized shapes selected for modeling. Some applications using the comparative values of the parameters of the homogenized structures are presented in this paper."}],"extern":"1","page":"82-91","_id":"21516","OA_type":"closed access","scopus_import":"1","keyword":["Rough surface topography","Stereology","Algorithm","Equivalent structure concept"],"oa_version":"None","publication_identifier":{"eissn":["1873-2577"],"issn":["0043-1648"]},"language":[{"iso":"eng"}],"volume":248,"publication":"Wear","month":"03","type":"journal_article","issue":"1-2","ddc":["530"],"title":"Description of rough surfaces using conformal equivalent structure concept: Part 1. Stereological approach","article_type":"original","date_updated":"2026-04-15T13:21:44Z","quality_controlled":"1"},{"extern":"1","page":"92-99","abstract":[{"text":"In our new approach, the notion of conformal equivalent structure is introduced by comparing the slope or gradient distributions of surface topography in 2D or 3D mode, respectively. The stereological approach described in Section 2 is, thus, confirmed by the numerical one which is proposed in this paper. The approach emphasizes the viability of the modeling and the limits observed in some practical applications of the study of rough surfaces via different approximation methods. The few divergences which have been noticed may be explained by the introduction of parameters such as skewness and kurtosis.","lang":"eng"}],"year":"2001","keyword":["Rough surface topography","Equivalent structure concept"],"scopus_import":"1","OA_type":"closed access","_id":"21517","day":"01","article_processing_charge":"No","date_published":"2001-03-01T00:00:00Z","citation":{"ama":"Roques-Carmes C, Bodin N, Monteil G, Quiniou JF. Description of rough surfaces using conformal equivalent structure concept: Part 2. Numerical approach. <i>Wear</i>. 2001;248(1-2):92-99. doi:<a href=\"https://doi.org/10.1016/s0043-1648(00)00563-9\">10.1016/s0043-1648(00)00563-9</a>","short":"C. Roques-Carmes, N. Bodin, G. Monteil, J.F. Quiniou, Wear 248 (2001) 92–99.","apa":"Roques-Carmes, C., Bodin, N., Monteil, G., &#38; Quiniou, J. F. (2001). Description of rough surfaces using conformal equivalent structure concept: Part 2. Numerical approach. <i>Wear</i>. Elsevier. <a href=\"https://doi.org/10.1016/s0043-1648(00)00563-9\">https://doi.org/10.1016/s0043-1648(00)00563-9</a>","chicago":"Roques-Carmes, Charles, N. Bodin, G. Monteil, and J.F. Quiniou. “Description of Rough Surfaces Using Conformal Equivalent Structure Concept: Part 2. Numerical Approach.” <i>Wear</i>. Elsevier, 2001. <a href=\"https://doi.org/10.1016/s0043-1648(00)00563-9\">https://doi.org/10.1016/s0043-1648(00)00563-9</a>.","ieee":"C. Roques-Carmes, N. Bodin, G. Monteil, and J. F. Quiniou, “Description of rough surfaces using conformal equivalent structure concept: Part 2. Numerical approach,” <i>Wear</i>, vol. 248, no. 1–2. Elsevier, pp. 92–99, 2001.","ista":"Roques-Carmes C, Bodin N, Monteil G, Quiniou JF. 2001. Description of rough surfaces using conformal equivalent structure concept: Part 2. Numerical approach. Wear. 248(1–2), 92–99.","mla":"Roques-Carmes, Charles, et al. “Description of Rough Surfaces Using Conformal Equivalent Structure Concept: Part 2. Numerical Approach.” <i>Wear</i>, vol. 248, no. 1–2, Elsevier, 2001, pp. 92–99, doi:<a href=\"https://doi.org/10.1016/s0043-1648(00)00563-9\">10.1016/s0043-1648(00)00563-9</a>."},"publication_status":"published","status":"public","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publisher":"Elsevier","date_created":"2026-03-30T12:22:47Z","doi":"10.1016/s0043-1648(00)00563-9","intvolume":"       248","author":[{"full_name":"Roques-Carmes, Charles","last_name":"Roques-Carmes","id":"e2e68fc9-6505-11ef-a541-eb4e72cc3e82","first_name":"Charles"},{"last_name":"Bodin","full_name":"Bodin, N.","first_name":"N."},{"full_name":"Monteil, G.","last_name":"Monteil","first_name":"G."},{"full_name":"Quiniou, J.F.","last_name":"Quiniou","first_name":"J.F."}],"date_updated":"2026-04-15T12:28:09Z","article_type":"original","quality_controlled":"1","issue":"1-2","type":"journal_article","title":"Description of rough surfaces using conformal equivalent structure concept: Part 2. Numerical approach","language":[{"iso":"eng"}],"month":"03","publication":"Wear","volume":248,"oa_version":"None","publication_identifier":{"issn":["0043-1648"],"eissn":["1873-2577"]}}]