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Effect of Microwave Irradiation on the Physical Properties and Structure of Silk Fibre

Xue Z.

Fibres & Textiles in Eastern Europe

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2018

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Vol. 26, no. 4 (130)

111--115

EN

Microwaves are high frequency radio waves which are capable of penetrating many materials and causing heat to be generated in the process. To investigate the effect of microwave irradiation on the physical properties as well as the chemical , surface morphological and fine structure of silk fabric, silk fabric was treated with microwave irradiation under a variety of conditions in terms of the power and time of microwave treatment. The breaking strength, elongation at break, and whiteness of the treated silk fabric in a wet state were investigated. The structures of the untreated and treated silk were investigated with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry(DSC)and X-ray diffraction (XRD). The results show that the physical properties of the treated silk fabrics were changed with the microwave irradiation time. The chemical and surface morphological structure as well as the decomposition temperatureand crystallinity of the treated silk were changed.

PL

Mikrofale to fale radiowe o wysokiej częstotliwości, zdolne do przenikania przez wiele materiałów i generowania ciepła w procesie. W celu zbadania wpływu promieniowania mikrofalowego na właściwości fizyczne, chemiczne, morfologię i strukturę tkaniny jedwabnej poddano ją promieniowaniu mikrofalowemu w różnych warunkach, pod względem mocy i czasu obróbki mikrofalami. Badano wytrzymałość na rozerwanie, wydłużenie przy zerwaniu i stopień bieli tkaniny jedwabnej poddanej obróbce mikrofalami w stanie mokrym. Struktury nietraktowanego i poddanego obróbce jedwabiu zbadano za pomocą spektroskopii w podczerwieni z transformatą Fouriera (FTIR), skaningowej mikroskopii elektronowej (SEM), różnicowej kalorymetrii skaningowej (DSC) i dyfrakcji rentgenowskiej (XRD). Wyniki pokazały, że właściwości fizyczne poddanych obróbce tkanin jedwabnych ulegały zmianie wraz z czasem naświetlania mikrofalami. Zmianie uległa chemiczna i powierzchniowa struktura, a także temperatura rozkładu i krystaliczność poddanego obróbce jedwabiu.

2

Transparent orthodontic archwires: A systematic literature review

Mikulewicz M., Gronostajski Z., Wielgus A., Chojnacka K.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 3

651--657

EN

Objective: The objective was to perform a systematic literature review to report the state of the art on the topic of transparent orthodontic archwires. Methods: The inclusion criteria: (1) transparent or translucent orthodontic wire, (2) production method presented, (3) physical properties tested. The exclusion criteria: (1) coated esthetic archwires, (2) repetitive publications without language limitations. Databases searched: Medline (via PubMed), Scopus, Embase and Ovid (from 1970.01.01 to 2016.02.01). Additional hand search was performed. The manual search was performed in selected orthodontic journals: American Journal of Orthodontic and Orthopedics, Angle Orthodontist, European Journal of Orthodontics (from 1995 to 2016.02.01). Results: Among 342 papers, 22 were selected for systematic review and divided into two groups: those commercially available on the market and those in research and development stage. The drawbacks associated with mechanical properties limit their widespread clinical use. Conclusions: The papers reported different materials presenting different characteristics by various methodology. For this reason it was difficult to objectively compare obtained results. Characterization of translucent archwires properties has shown that further studies are required to confirm the usefulness of this type of wires, also in clinical practice.

3

Characterization of espey colemanite and variation of its physical properties with temperature

Celik A. G., Cakal G. O.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 1

66--76

EN

It is important to characterize boron containing minerals because of their uses in a wide range of applications. The purpose of this study is to characterize Espey colemanite by minerological, petrographical and thermal means and to investigate the variation of its physical properties with temperature (up to 600 °C). Colemanite, having a non-porous crystalline structure, was found to consist of 35.8% B2O3 and 30.5% SiO2. The thermal decomposition of colemanite occurred within the temperature range of 300–600 °C. It was found that calcination, a thermal treatment method, influenced the physical properties of colemanite. The highest surface area, 131.9 m2/g, was obtained at 500 °C. The physical properties were found to have high statistical relation.

4

Expanded perlite aggregate characterization for use as a lightweight construction raw material

Celik A. G., Kilic A. M., Cakal G. O.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 2

689--700

EN

The purpose of this study is to investigate the use of İzmir (Menderes-Cumaovası) expanded perlite as a construction raw material by determining its characteristic properties, as well as its physical properties at different temperatures (up to 600°C). The perlites, having glassy, porous structure, were found to contain 70.68% SiO2 and 13.04% Al2O3. The physical properties of the perlites changed with temperature. The highest surface area, 524 m2/g, was obtained at 400°C. The physical properties were found to have high statistical relation. It was concluded that expanded perlite aggregates could be used as a construction raw material.