University of Maribor

About: University of Maribor is a education organization based out in Maribor, Slovenia. It is known for research contribution in the topics: Population & KEKB. The organization has 3987 authors who have published 13077 publications receiving 258339 citations. The organization is also known as: Univerza v Mariboru.

Compatibilization of polypropylene/polystyrene blends with poly(styrene-b-butadiene-b-styrene) block copolymer

Abstract: The compatibilizing effect of the triblock copolymer poly(styrene-b-butadiene-b-styrene) (SBS) on the morphology and mechanical properties of immiscible polypropylene/polystyrene (PP/PS) blends were studied. Blends with three different weight ratios of PP and PS were prepared and three different concentrations of SBS were used for investigations of its compatibilizing effects. Scanning electron microscopy (SEM) showed that SBS reduced the diameter of the PS-dispersed particles as well as improved the adhesion between the matrix and the dispersed phase. Transmission electron microscopy (TEM) revealed that in the PP matrix dispersed particles were complex “honeycomblike” aggregates of PS particles enveloped and joined together with the SBS compatibilizer. Wide-angle X-ray diffraction (WAXD) analysis showed that the degree of crystallinity of PP/PS/SBS slightly exceeded the values given by the addition rule. At the same time, addition of SBS to pure PP and to PP/PS blends changed the orientation parameters A110 and C significantly, indicating an obvious SBS influence on the crystallization process in the PP matrix. SBS interactions with PP and PS influenced the mechanical properties of the compatibilized PP/PS/SBS blends. Addition of SBS decreased the yield stress and the Young's modulus and improved the elongation at yield as well as the notched impact strength in comparison to the binary PP/PS blends. Some theoretical models for the determination of the Young's modulus of binary PP/PS blends were used for comparison with the experimental results. The experimental line was closest to the series model line. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 2625–2639, 1998

Measurement of the electroweak penguin process B → Xsℓ+ℓ-

Abstract: We report the first measurement of the branching fraction for the inclusive decay B → X s l + l - , where l is either an electron or a muon, and X s is a hadronic recoil system that contains an s quark. We analyzed a data sample of 65.4 x 10 6 B meson pairs collected with the Belle detector at the KEKB e + e - asymmetric-energy collider. We find B(B → X s l + l - ) = [6.1 ′ 1.4(stat) + 1 . 4 - 1 . 1 (syst)] × 10 - 6 for dilepton masses greater than 0.2 GeV/c 2 .

Miniature fiber optic pressure sensor for medical applications

Abstract: Presents a theoretical description, fabrication and experimental investigation of miniature optical fiber pressure sensor for invasive measurement of blood pressure. Sensor measures only 125 /spl mu/m in diameter. The essential element is thin polymer diaphragm that is positioned inside a hollow end of the optical fiber. The cavity at the fiber end is made by wet etching in diluted HF acid. Thus the Fabry-Perot interferometer is formed between the inner fiber-cavity interface and the diaphragm. Deflection of the diaphragm and so pressure magnitude is determined by reading the reflectance spectrum of the sensing Fabry-Perot interferometer using broadband illumination. The configuration of Fabry-Perot interferometer at the optical fiber end makes sensor immune from bending of optical fiber and optical power fluctuations of light source. We deployed sensor prototype from 125 /spl mu/m-diameter optical fiber. It is optimized for human blood pressure range, namely from 0 to 40 kPa (0 to 300 mmHg) with 1 mmHg resolution. Our fabrication technique offers simple and low-cost disposable medical pressure sensor production.

Accuracy in strategy imitations promotes the evolution of fairness in the spatial ultimatum game

Abstract: Spatial structure has a profound effect on the outcome of evolutionary games. In the ultimatum game, it leads to the dominance of much fairer players than those predicted to evolve in well-mixed settings. Here we show that spatiality leads to fair ultimatums only if the intervals from which the players are able to choose how much to offer and how little to accept are sufficiently fine-grained. Small sets of discrete strategies lead to the stable coexistence of the two most rational strategies in the set, while larger sets lead to the dominance of a single yet not necessarily the fairest strategy. The fairest outcome is obtained for the most accurate strategy imitation, that is in the limit of a continuous strategy set. Having a multitude of choices is thus crucial for the evolution of fairness, but not necessary for the evolution of empathy.