Brno University of Technology

About: Brno University of Technology is a education organization based out in Brno, Czechia. It is known for research contribution in the topics: Fracture mechanics & Filter (video). The organization has 6339 authors who have published 15226 publications receiving 194088 citations. The organization is also known as: Vysoké učení technické v Brně & BUT.

Influence of removal of microbial inhibitors on PHA production from spent coffee grounds employing Halomonas halophila

Abstract: The valorization of food waste is the sustainable way how to handle resources wisely. Spent coffee grounds (SCGs) are waste products of the instant coffee production and coffee brewing. The potential of Halomonas halophila to produce polyhydroxyalkanoates (PHA) from fermentable sugars derived from SCGs has been studied. This organism was able to process SCG hydrolysates as a carbon source for its growth. Diluted acid hydrolysis (4.0 vol.% sulfuric acid, 120 min, 100 °C) has been employed, and three different SCG hydrolysates from non-modified SCGs, defatted SCGs and defatted SCGs with the eliminated phenolics have been prepared. However, in shake flask fermentation cultures, the growth of H. halophila was entirely inhibited on all the hydrolysates. Therefore, the hydrolysates have been detoxified using sorbent based on styrene-divinylbenzene based resins. When H. halophila was grown on detoxified hydrolysates, poly(3-hydroxybutyrate) (P3HB) was accumulated during 72 h. The biopolymer was characterized by gas chromatography, and size exclusion chromatography coupled with multiangle light scattering and differential refractometry. PHB titers reached 0.95 g/L with PHB content in bacteria cell dry mass 27% (wt/wt), the molecular weight of the produced polymer was about 440–825 kDa. This study demonstrates that at least the detoxification of SCG hydrolysates with sorbent was necessary to promote the fermentation of H. halophila. Moreover, the extraction of coffee oil and phenolics from SCG as a detoxification pretreatment step contributes to the increase of economic and environmental values of spent coffee grounds in the case of the cascading utilization and resource recovery.

Yet Faster Ray-Triangle Intersection (Using SSE4)

Abstract: Ray-triangle intersection is an important algorithm, not only in the field of realistic rendering (based on ray tracing) but also in physics simulation, collision detection, modeling, etc. Obviously, the speed of this well-defined algorithm's implementations is important because calls to such a routine are numerous in rendering and simulation applications. Contemporary fast intersection algorithms, which use SIMD instructions, focus on the intersection of ray packets against triangles. For intersection between single rays and triangles, operations such as horizontal addition or dot product are required. The SSE4 instruction set adds the dot product instruction which can be used for this purpose. This paper presents a new modification of the fast ray-triangle intersection algorithms commonly used, which-when implemented on SSE4-outperforms the current state-of-the-art algorithms. It also allows both a single ray and ray packet intersection calculation with the same precomputed data. The speed gain measurements are described and discussed in the paper.

Contrasting Origins of the Mixed (NYF + LCT) Signature in Granitic Pegmatites, with Examples from the Moldanubian Zone, Czech Republic

Abstract: Two granitic pegmatites with mixed (NYF + LCT) signatures from the Moldanubian Zone, Czech Republic, were examined to determine their origin. On the basis of geological setting, paragenesis, geochemical modeling and chemical composition of rocks and minerals, two contrasting modes of origin were discerned. The Li-bearing (lithium micas + elbaite) Kracovice pegmatite, with "amazonite", samarskite and fergusonite, is the product of the strong fractionation of pegmatite-forming melt derived from the orogenic I-type Trebic pluton. Geological, petrological, compositional and isotopic data from this ultrapotassic melasyenite-melagranite point to mixing of a mantle-derived magma with (leuco) granitic melt from crustal rocks. The granite-pegmatite system of the Trebic pluton and the mainly Li-bearing Kracovice pegmatite are typical examples of the mixed (NYF + LCT) petrogenetic family. The contaminated elbaite-subtype pegmatite Blizna I, Cesky Krumlov Unit, with lithium tourmalines (elbaite, liddicoatite, uvite), primary REE minerals [bastnasite-(Ce), parisite-(Ce), allanite-(Ce)] and Ca(Mg)-rich minerals (diopside, uvite, titanite), gained its mixed signature through a unique pre-emplacement process involving the external contamination with Ca, Mg and REE of an evolved (LCT) pegmatite-forming melt by distal carbonatite-like marbles with an NYF signature. Despite the clearly mixed-signature mineralogy and geochemistry, the Blizna I pegmatite represents a special type of contaminated LCT pegmatite rather than a member of the mixed family.