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Thermoplastic polyurethanes for mining application processing by 3D printing

Mrówka M., Szymiczek M., Lenża J.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 95, nr 1

13--19

EN

Purpose: Thermoplastic polyurethanes (TPU) found application in mining. Due to the excellent processing properties, thermoplastic polyurethanes can be also use to make elements that would facilitate miner's work. These elements, however, differ in dimensions depending on the person who is going to use them, that is why they should be personalized. In case of all the above studies, the elements or stuffs were made by means of the injection method. This method limits the possibility of producing mining’s stuff only to models that have a mould. The 3D printing technology developing rapidly throughout the recent years allows for high-precision, personalized elements’ printing, made of thermoplastic materials. Design/methodology/approach: The samples from thermoplastic polyurethanes were made using 3D printing and then subjected to the aging process at intervals of 2, 7 and 30 days. The samples were then subjected to a static tensile tests, hardness tests and FT-IR spectroscopy. Findings: The obtained results of mechanical tests and IR analyses show that the aging process in mine water does not affect the mechanical properties of the samples regardless of the aging time. IR spectral analysis showed no changes in the structure of the main and side polyurethane chains. Both mechanical and spectral tests prove that polyurethanes processed using 3D printing technology can be widely used in mining. Research limitations/implications: Only one type of TPU was processed in this work. Further work should show that synthetic mine water does not degrade the mechanical properties of other commercially available TPUs. Practical implications: The additive technology allows getting elements of mining clothing, ortheses, insoles or exoskeleton elements adapted to one miner. Originality/value: The conducted tests allowed to determine no deterioration of the mechanical properties of samples aged in synthetic mine water. TPU processing using 3D printing technology can be used in mining.

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Differences in the perilymph fluid stimulation before and after experimental stapedotomy

Kwacz M., Mrówka M., Wysocki J.

Acta of Bioengineering and Biomechanics

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2012

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Vol. 14, no. 2

67-73

EN

A stapedotomy surgery using a piston stapes prosthesis significantly modifies the perilymph fluid stimulation level and always leads to alteration of conditions in sound transmission through the cochlea. This paper shows the results of non-contact measurements of the stapes head velocity, a Teflon piston stapes prosthesis velocity and round window velocity conducted in freshly harvested human cadaver temporal bone specimens. The vibration patterns were measured within the frequency range of 0.4-10 kHz at the sound pressure level of 90 dB administered to the external auditory canal in the same specimen before and after experimental stapedotomy. It was shown that the vibrations of the stapes Teflon piston prosthesis and the physiological stapes are similar and approximately five-fold lower amplitude of the round window membrane vibrations compared to a physiologic situation is caused by piston shape of the stapes prosthesis. The results in this report are the part of a larger study designed to develop a new type of chamber stapes or whole middle ear prosthesis.

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System pomiarowy do badań eksperymentalnych mechaniki ucha środkowego

Kwacz M., Wysocki J., Mrówka M.

Pomiary Automatyka Kontrola

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2011

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R. 57, nr 1

25-29

PL

W artykule opisano system pomiarowy do bezkontaktowego pomiaru parametrów drgań elementów strukturalnych narządu słuchu. Zaproponowano oryginalną metodykę pomiarów eksperymentalnych drgań błony okienka okrągłego w warunkach in-vitro oraz stwierdzono, że technika laserowej wibrometrii Dopplerowskiej jest przydatnym narzędziem badawczym w skali mikro- i nanometrowej nie tylko obiektów technicznych ale również obiektów biologicznych.

EN

This paper presents the measuring system for non-contact measurements of vibration parameters of the hearing organ structural elements. An original methodology for in-vitro measurements of the round window membrane vibration is proposed. It was found that the Laser Doppler Vibrometry (LDV) technique is a useful research tool in micro- and nanometer scale not only technical but also biological objects. Section 1 shows the hearing organ anatomic structure (Fig. 1) and presents the applicability of the LDV method. Section 2 contains a brief review of the literature [1-16] presenting the methodology of experimental middle ear mechanics carried out by the LDV technique. Subsection 2.1 describes the various ways of making the temporal bone preparations and contains diagrams showing examples of such preparations (Fig. 2). Subsections 2.2 and 2.3 deal with a system that forces acoustic vibrations in the test preparation and the optical system allowing measurements of the velocity or displacement amplitude of vibrating elements. Section 3 presents the authors' methodology for experimental measurements of the round window membrane vibration. There is shown the scheme of experimental measurements and view of the part of the test stand (Fig. 4) as well as the functional diagram (Fig. 5), block diagram and view of the measurement system (Fig. 6). In Section 4 there is described the possibility of using the developed methodology and the measurement system.

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Pomiary drgań błony okienka okrągłego metodą laserowej wibrometrii Dopplerowskiej

Kwacz M., Wysocki J., Mrówka M.

Pomiary Automatyka Kontrola

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2011

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R. 57, nr 5

471-478

PL

W artykule opisano wykonane po raz pierwszy w Polsce bezkontaktowe pomiary parametrów drgań błony okienka okrągłego (RW) w świeżych preparatach ludzkiej kości skroniowej wykonane metodą laserowej wibrometrii Dopplerowskiej (LDV). Badania przeprowadzono systemem skanującego wibrometru laserowego PSV 400 (Polytec, Waldbronn, Germany). Pokazano charakterystyki amplitudowo-czestotliwościowe oraz fazowo-czestotliwościowe drgań błony RW dla preparatu w warunkach anatomii prawidłowej (stan fizjologiczny). Charakterystyki wyznaczono w zakresie częstotliwości od 400 Hz do 10000 Hz przy 90 dB poziomie natężenia dźwięku podawanego do zewnętrznego przewodu słuchowego. Stwierdzono, że pomiary parametrów drgań błony okienka okrągłego mogą różnicować rezultaty słuchowe osiągane po chirurgicznych operacjach rekonstrukcji łańcucha kosteczek słuchowych, szczególnie w przypadku operacji otosklerozy.

EN

The paper describes non-contact measurements of round window (RW) membrane vibration parameters with use of a Laser Doppler Vibrometer (LDV) in freshly dissected specimens of a human temporal bone - a procedure conducted in Poland for the first time. In the research - the Scanning Laser Vibrometer system - PSV 400 (Polytec, Waldbronn, Germany) - was used. The paper presents amplitude -frequency and phase-frequency characteristics of the RW membrane vibrations in a specimen of correct anatomy (physiological conditions). The characteristics were measured within the 400 Hz - 10000 Hz range with a 90 dB sound pressure level applied to the external ear canal. It is shown that measurements of the round window membrane vibrations may be a tool for evaluating hearing results of surgical ossicular chain reconstruction, especially in case of otosclerosis operation. In Section 1 an anatomical structure of the organ of hearing is shown (Fig. 1) and measurement methods for the round window membrane vibrations described in literature [1-16] are presented. Section 2 contains description of the measurement method used by the authors. In Subsection 2.1 there is a short review of literature [1, 3, 12,19-21] regarding methods for temporal bone preparation and a description of the method for preparing such specimens worked out by the authors. Subsections 2.2 and 2.3 deal with description of the research system and measurement procedure used for measurements of the round window membrane vibrations. Section 3 presents the results of experimental investigations on parameters of the round window membrane vibrations performed by the authors. The results are shown in the form of the amplitude-frequency characteristics, isoamplitude charts and 3D visualization. In the summary (Section 4) the characteristics of the round window membrane vibrations are analysed and applicability of the conducted investigations to evaluating the hearing results of surgical ossicular chain reconstruction is proved.