Bigger font | Smaller font

Search the digital library catalog Help

Query: search in
search in
search in
search in
* old and bologna study programme


1 - 10 / 1181
First pagePrevious page12345678910Next pageLast page
Analysis of dynamics and fit of diving suits
Maja Mahnić, Slavenka Petrak, Jelka Geršak, Tomislav Rolich, 2017, published scientific conference contribution

Keywords: textile fabrics, 3D body scanning, 3D simulation, garment design
Published: 04.04.2018; Views: 15; Downloads: 5
.pdf Full text (1,07 MB)

Synthesis of PMMA/ZnO nanoparticles composite used for resin teeth
Danica Popović, Rajko Bobovnik, Silvester Bolka, Miroslav Vukadinovič, Vojkan Lazić, Rebeka Rudolf, 2017, original scientific article

Abstract: Wear resistance is one of the most important physical properties of the artificial teeth used in acrylic dentures. The goal of this research was to synthesize a new composite material made of matrix Poly-(methyl methacrylate)-PMMA with different percentages (2 % and 3 % of volume fractions) of zinc-oxide nanoparticles (ZnO NPs) as reinforcing elements, to improve its mechanical properties. The dynamic mechanical behaviour of this composite was studied through the DMA method in comparison to the pure PMMA supported by the characterization of their microstructures. Then the wear resistance was analysed on the samples, which were prepared in the form of teeth. In this context their vertical height loss was measured after 100,000 chewing cycles on a chewing simulator, before and after the artificial thermal ageing. Investigations showed that the PMMA/ZnO NP composites dampened the vibrations better than the pure PMMA, which could be assigned to the homogenous distribution of ZnO NPs in the PMMA matrix. It was found that the mean vertical height loss for the pure PMMA teeth was significantly higher (more than 4 times) compared to composite teeth made with ZnO NPs. Introducing the thermal artificial ageing led to the finding that there was no effect on the height loss by the composite material with 3 % of volume fractions of ZnO NPs. Based on this it was concluded that PMMA/ZnO NPs composites showed improved in-vitro wear resistance compared to acrylic-resin denture teeth, so this new composite material should be preferred when occlusal stability is considered to be of high priority.
Keywords: poly-methyl methacrylate, PMMA, zinc-oxide nanoparticles, composite, resin teeth
Published: 12.12.2017; Views: 48; Downloads: 3
.pdf Full text (1,55 MB)

Synergistic chemo-enzymatic hydrolysis of poly (ethylene terephthalate) from textile waste
Felice Quartinello, Simona Vajnhandl, Julija Volmajer Valh, Thomas Farmer, Bojana Vončina, Aleksandra Lobnik, Enrique Herrero Acero, Alessandro Pellis, Georg M. Gübitz, 2017, original scientific article

Abstract: Due to the rising global environment protection awareness, recycling strategies that comply with the circular economy principles are needed. Polyesters are among the most used materials in the textile industry; therefore, achieving a complete poly(ethylene terephthalate) (PET) hydrolysis in an environmentally friendly way is a current challenge. In this work, a chemo-enzymatic treatment was developed to recover the PET building blocks, namely terephthalic acid (TA) and ethylene glycol. To monitor the monomer and oligomer content in solid samples, a Fourier-transformed Raman method was successfully developed. A shift of the free carboxylic groups (1632 cm$^{−1}$) of TA into the deprotonated state (1604 and 1398 cm$^{−1}$) was observed and bands at 1728 and 1398 cm$^{−1}$ were used to assess purity of TA after the chemo-enzymatic PET hydrolysis. The chemical treatment, performed under neutral conditions (T = 250 °C, P = 40 bar), led to conversion of PET into 85% TA and small oligomers. The latter were hydrolysed in a second step using the Humicola insolens cutinase (HiC) yielding 97% pure TA, therefore comparable with the commercial synthesis-grade TA (98%).
Keywords: textile waste, waste recycling
Published: 16.11.2017; Views: 106; Downloads: 2
.pdf Full text (304,48 KB)

Semi-analytical method for solving Fokker-Planck's equations
Majeed Ahmed Al-Jawary, Ghassan Hasan Radhi, Jure Ravnik, 2017, original scientific article

Abstract: In this paper, the linear and nonlinear Fokker-Planck equations (FPE) are solved by a semi-analytical iterative technique. This technique was proposed by Temimi and Ansari (TAM) in 2011. It is used to obtain the exact solutions for the 1D, 2D and 3D FPE. We solve several linear and nonlinear examples to show that the method is efficient and applicable. The results demonstrate that the presented method is very effective and reliable and does not require any restrictive assumptions for nonlinear terms. A symbolic manipulator Mathematica®10 was used to evaluate terms in the iterative process.
Keywords: Fokker-Planck's equation, semi-analytical method, analytic solution, Brownian motion, Kolmogorov's equation
Published: 03.11.2017; Views: 57; Downloads: 3
.pdf Full text (476,67 KB)

Search done in 0.2 sec.
Back to top
Logos of partners University of Maribor University of Ljubljana University of Primorska University of Nova Gorica