Application of algal biomass for enhanced acclimatization of orchids

Algae produce plant growth regulators (PGRs), similar to higher plants. To study this feature, freeze-dried and ultrasonicated algal biomass was applied to support the development of certain orchids. An in vitro and an ex vitro experiment were carried out. In case of Phalaenopsis and Paphiopedilum, the nutrition medium was supplemented with the biomass of five algal strains at a concentration of 0.5 gL-1 in the in vitro experiment. This treatment enhanced the development of plants, but different strains depending on orchid species proved to be efficient. In Oncidium cultures different concentrations of MACC-612 were applied as a supplementation of nutrition media. Results showed, that higher concentrations (0.5 – 1 gL-1) evolved a salutary effect on the plant growth. In the ex vitro experiment orchids were grown on algal free media under sterile conditions. After that they were potted into the greenhouse and treated eleven times with different concentrations of algal suspension. After three months of acclimatization the lower concentrations (0.1 – 0.2 gL-1) of algal biomass applied in the cultures of Phalaenopsis, Paphiopedilum and Oncidium exerted a positive effect

Natural substances in tissue culture media of higher plants

Plant cell and tissue cultures are characterized by the use of isolated parts of plant obtained from an intact plant body and kept on, or in a suitable nutrient medium. This nutrient medium functions as replacement for the cells, tissue, or conductive elements originally neighbouring the explant. The exact conditions required to initiate and sustain plant cells in culture, or to regenerate intact plants from cultured cells, are different for each plant species. The empirical approach has shown that three factors, namely explant choice, medium composition, and control of the physical environment are important in successful cultures. When the completely defined plant culture media did not give the desired results, employing natural substances have beneficial effects on in vitro plant cell and tissue cultures. The composition of different culture media and the effects of natural compounds, including the supernatant and freeze-dried biomass of well-growing algal strains of Mosonmagyaróvár Algal Culture Collection (MACC), are presented in this short review

Analysis of Thermogravimetric and Dynamic Mechanical Properties of PLA/PBS Blends Doped With Zinc Oxide Nanoparticles

In the present work, PLA-PBS blends of 80/20 weight ratio were doped with zinc oxide (2.5; 5; 7.5 and 10 phr) and the flow, thermogravimetric and thermomechanical behaviour of the resulting blends were investigated. Using capillary plasstometry, thermogravimetry (TGA) and dynamic mechanical analysis (DMA), it was found that the increase in zinc oxide content resulted in an increase in the flow indices (MFI, MVR), as well as in the storage and loss modulus values, and a decrease in the thermal stability and glass transition temperature

Cink-oxid nanorészecskékkel adalékolt PLA/PBS keverékek termogravimetriai és dinamikus mechanikai tulajdonságainak vizsgálata

Jelen munkában 80/20 tömegarányú PLA-PBS keverékeket adalékoltunk cink-oxidoddal (2,5; 5; 7,5 és 10 phr arányban), majd az így létrehozott keverékek folyási, termogravimetriai és termomechanikai viselkedését vizsgáltuk. Kapillárisképlékenység-mérés, termogravimetria (TGA) és dinamikus mechanikai analízis (DMA) segítségével megállapítottuk, hogy a cink-oxid-tartalom növelésének hatására a folyási mutatószámok (MFI, MVR), továbbá a tárolási és veszteségi modulusz értékei növekedtek, a termikus stabilitás és az üvegesedési átmeneti hőmérséklet csökkent

Modeling the Deformation and the Failure Process of Glass Woven Fabrics Based on the Fibre-Bundle-Cells Theory

In this study, we modeled the deformation and failure behavior of different glass woven fabrics under uniaxial tension using the Fibre Bundle Cells-modeling method. The difference between the analytical, phenomenological model curve and the mean curve calculated from the measurement results was classified by the relative mean squared error (RMSE), which is closely related to the coefficient of determination. This value was less than 3.6% in all the examined cases, which indicated good modeling

Üvegszövetek deformációs és tönkremeneteli folyamatának szálkötegcella-elméleten alapuló modellezése

Ebben a kutatásban különböző üvegszövetek egytengelyű húzás hatására mutatott deformációs és tönkremeneteli viselkedését modelleztük a szálkötegcella-alapú modellezéssel. Az általunk felállított analitikus, fenomenológiai modellgörbe és a mérési eredményekből meghatározott átlaggörbe közötti eltérést a determinációs együtthatóval szoros összefüggésben álló relatív átlagos négyzetes hibával (RÁNH) minősítettük. Ez az érték minden vizsgált esetben kevesebb mint 3,6% volt, ami alapján a modellezés kifejezetten jónak tekinthető

Carbon Isotope Investigation of Freshwater Tufa Precipitation in Karst Streams of Bükk Mountains (Hungary)

Recent freshwater tufa precipitation and its parent water were investigated at Szalajka valley, Sebesvíz and Dobrica Spring (Bükk Mts., Hungary). The aim of the study is to analyse the carbon isotope dynamics of freshwater tufa precipitated in karstic streams between the spring water and the first significant tufa barrage using field measurements, water chemistry, and carbon isotope analysis. A further aim was to examine the fossil tufa precipitations in recently active areas and their neighbourhood to determine their age using the 14C method. Based on the 3H content the water samples are relatively young (<10 y). To calibrate the calendar age of older tufas, dead carbon proportion (dcp) were determined in the recently formed freshwater tufas. The lowest dcp of the recent freshwater tufas was estimated at Sebesvíz (9.6±1.3%), the highest at Szalajka (16.4±2.4%) and a moderate value at Dobrica Spring (13.8±2.2%). Due to the rapid decrease in atmospheric 14C level we have to compensate the atmospheric 14C drop between the water infiltration time and the deposition time of fresh carbonates to compensate the bomb-effect. The oldest fossil tufa age (BC 6421-6096) was found at Sebesvíz located around 20 metres away from the riverbed, while the youngest fossil tufa ages (a few years/decades old) were found in the recently active area at all sites