Ekologické zemědělství - informační bulletin č.11: Přímý prodej

Jednotným tématem informačního bulletinu č. 11 je Přímý prodej biopotravin: Předpoklady pro přímý prodej. Přímý prodej produktů rostlinného původu. Jakost ovoce z ekologického pěstování. BIO na tržnici v St.Gallenu. Přímý prodej produktů živočišného původu. Marketing v přímém prodeji. Jednotlivé způsoby přímého prodeje ekologických produktů. Příklady ekologicky hospodařících zemědělců s přímým prodejem. Společné ztržňování bioproduktů

Query Expansion and Evolution of Topic in Information Retrieval Systems

Approach based on clustering will be described in our paper

Data from: Disentangling evolutionary, environmental and morphological drivers of plant anatomical adaptations to drought and cold in Himalayan graminoids

Understanding what determine plants ability to survive drought and cold is crucial for predicting how plants may respond to ongoing climate change. Plant survival strategies are usually characterized by morphological and physiological adaptations, while their underlying anatomical settings are largely unknown. Woody angiosperms and herbaceous dicots have repeatedly evolved small water transporting conduits and large storage parenchyma tissues at colder or drier places to cope with freezing- and drought-induced damages. However, whether these adaptations are also valid for graminoids remains unclear. Here we show that stem anatomical variations in grasses, sedges and rushes dominating in western Himalayan grasslands are driven by elevation and soil moisture via control over aboveground plant stature and belowground clonal growth, while phylogenetic constraints have only a weak effect. Phylogenetic comparative analyses controlling for confounding factors showed that the elevation-related cooling controls the conductive system through reduced vessel diameter and extended assimilatory and storage tissues with more chlorenchyma and less sclerenchyma around vessels. The soil moisture deficit, on the other hand, determines stabilization structures by promoting short-rhizomatous turf graminoids with hollow stems, thicker epidermis and deep adventitious roots in dry steppes and semi-deserts. Saline wetlands and moist alpine pastures promote long-rhizomatous short-stature plants with lower need for mechanical support (absence of hollow stem) and exposure to high evaporative forcing (thinner epidermis). Observed trends of decreasing vessel sizes and lignification rate with elevation supports the existing knowledge that narrower vessels and extensive parenchyma assist plants to grow in cold environments by avoiding freezing-induced cavitation. Our results bring novel information on ecological drivers influencing the evolution of anatomical adaptations in high mountain graminoids. Distinct grassland types, covering elevations from 2650 to 6150 m, harbor unrelated species with different evolutionary histories that have converged towards similar anatomical structures

Dynamics analysis of cavitation disintegration of microparticles during nanopowder preparation in a new Water Jet Mill (WJM) device

A physical analysis of cavitation-based implosive breakage of solid particles focusing on practical application during fine particle disintegration in a liquid suspension is submitted in the present paper. The physical source of the cavitation dynamics phenomena involved is an extreme velocity gradient induced by an ultrahigh-energy liquid jet mixing together with a slow liquid suspension of milled particles. Extreme tensile stresses occurring at velocity gradients over 1000 ms−1mm−1 at the operating temperature of 65 °C generates high-intensity pure vapor cavitation in the degassed water dispersion with extreme values of impact pressure in the final of bubble implosions on particle surfaces. Preparation of silicon nanoparticles with median diameter approximately 148 nm using a newly developed “Water Jet Mill” (WJM) device is demonstrated in the present article as an example of application of the aforementioned disintegration method as well as of theoretical analysis of this method. The disintegration method is characterized by a high potential for milling of submicron particles with high efficiency.Web of Science22564363