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New doctoral dissertation

June 5, 2025

VILNIUS TECH Library invites you to follow the published new dissertations. The dissertation „Research and analysis of acoustic properties of composite panels from tyre textile fibre“ prepared by VILNIUS TECH Robert Ružickij. The dissertation was prepared in 2020–2025. Scientific consultant – Assoc. Prof. Dr Raimondas Grubliauskas.

The dissertation was defended at the public meeting of the Dissertation Defence Council of the Scientific Field of Environmental Engineering in the Aula Doctoralis Meeting Hall of Vilnius Gediminas Technical University at 2 p. m. on 5 June 2025.

The dissertation investigates tyre textile fibre and composite sound-absorbing panels based on this material. The main research object is composite sound-absorbing panels made of tyre textile fibre. The dissertation aims to create a sound-absorbing panel based on tyre textile fibre intended to improve acoustic comfort in the room. The work solves several tasks related to the acoustic characterisation of tyre textile fibre and its composites, investigation of physical properties, prediction of the sound absorption coefficient beyond the measurements, life cycle assessment and analysis of the composite sound absorbing panels, and lastly, optimal composition determination using the TOPSIS method of multicriteria decision analysis. The dissertation consists of an introduction, three chapters, general conclusions, a recommendation, references, and a list of the author’s publications on the dissertation topic. The introductory chapter describes the research problem, the relevance of the dissertation, and the research object, distinguishes the dissertation tasks, and the purpose and tasks, indicates the research methodology, the scientific novelty, and the practical significance of the research results, and presents the defended statements. The introduction chapter closes with a list of the author’s publications, presentations at conferences, and the structure of the dissertation. The First Chapter investigates the possibilities of using fibrous materials, the assessment of the dependence of the sound absorption of porous materials on various parameters, such as material density, thickness, the amount of binding material in the composite, etc., and the environmental impact assessment modelling programme is discussed. The Second Chapter presents methods of sample characterisation and sample preparation, experimental laboratory transfer function research method, method of conversion of sound absorption coefficient to αw value, potential environmental impact assessment of composite sound absorbing panels, and TOPSIS methods of multicriteria decision analysis. The Third Chapter presents the results of experimental studies, life cycle modelling and their analysis, and the optimal composition of the composite sound absorbing panel determined by the TOPSIS method. Nine scientific articles have been published on the dissertation topic: two in scientific journals included in the Web of Science list with a citation index, two in scientific journals included in the Web of Science list without a citation index, and five in conference proceedings. A patent was issued by the Lithuanian State Patent Office. Eight conference presentations were made on the dissertation topic in Lithuania and abroad.

Doctoral dissertation readers can search via VILNIUS TECH Virtual Library.

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