27 research outputs found
X-ray imaging with compound refractive lens and microfocus X-ray tube
Compound refractive lenses (CRL), consisting of a lot number in-line concave microlenses made of low-Z material were studied. Lenses with focal length 109 mm and 41 mm for 8-keV X-rays, microfocus X-ray tube and X-ray CCD camera were used in experiments. Obtained images show intensity distribution of magnified microfocus X-ray source focal spot. Within the experiments, one lens was also used as an objective lens of the X-ray microscope, where the copper anode X-ray microfocus tube served as a source. Magnified images of gold mesh with 5 microns bars were obtained. Theoretical limits of CRL and experimental results are discussed
Distributions of vascular plants in the Czech Republic. Part 8
The eighth part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 106 taxa in the genera Abutilon, Achillea. Arctium, Arenaria. Arnoseris, Carex. Chamaecytisus, Cornus, Diphasiastrum, Echinops. Galeopsis. Galium, Huperzia, Isoetes. Lyco-podiella. Lycopodium. Moehringia, Orobanche, Phelipanche, Prunus, Ranunculus, Selaginella. Stachys, Telekia, Typha and Zannichellia. These maps were produced by taxonomic experts based on examined herbarium specimens, literature and field records. Many of the studied native species are on the national Red List. They are represented by plants that are rare in the Czech Republic, in extreme cases confined to single sites (Arenaria grandiflora. Galium austriacum, Isoetes echinospora, I. lacustris and Orobanche teucrii). or that have experienced a considerable decline (e.g. Arnoseris minima. Carex hordeistichos, C. secalina. Diphasiastrum tristachyum and Lycopodiella inundata), or a combination of both (e.g. Orobanche artemisiae-campestris. O. coerulescens, Phelipanche arenaria. Ph. caesia and Stachys germanica). Three species (Moehringia muscosa, Selaginella helvetica and Typha minima) have been extirpated from this country. Alien species are represented by both archaeophytes (e.g. Arctium lappa, A. tomentosum, Orobanche minor, Stachys annua and S. arvensis) and neophytes (e.g. Abutilon theophrasti and Typha laxmannii). Two species have become invasive: Echinops sphaerocephalus spreads mainly in dry and disturbed habitats along roads and railways in warm lowlands, whereas Telekia speciosa is now locally frequent in various habitats mainly at middle and high elevations. Echinops bannaticus is reported here as a new alien species in the Czech Republic that occasionally escapes from cultivation. Spatial distributions and often also temporal dynamics of individual taxa are shown in maps and documented by records included in the Pladias database and available in electronic appendices. The maps are accompanied by comments that include additional information on the distribution, habitats, taxonomy and biology of the taxa
Ion emission from plasmas produced by femtosecond pulses of short-wavelength free-electron laser radiation focused on massive targets: an overview and comparison with long-wavelength laser ablation
We report on ion emission from plasma produced on thick targets irradiated with nanosecond and femtosecond pulses delivered by mid-ultraviolet and soft x-ray lasers, respectively. To distinguish between different ion acceleration mechanisms, the maximum kinetic energy of ions produced under different interaction conditions is plotted versus laser fluence. The transformation of the time-of-flight detector signal into ion charge density distance-of-flight spectra makes it possible to determine the mean kinetic energy of the fastest ion groups based on the influence of the acoustic velocity of ion expansion. This allows obtaining additional characteristics of the ion production. The final energy of the group of fast ions determined using the ion sound velocity model is an order of magnitude larger in the fs-XFEL interaction than in the ns-UV one. On the contrary, the ablation yield of ions in our experiment is seven orders of magnitude greater when applying ns-UV laser pulses, not only due to higher energies of UV laser pulses, but also due to a significant difference in interaction and ion formation mechanisms
Porozumeni telefonickemu dotazu pro automatickou dopravni informacni sluzbu.
The presented thesis concerns the spoken language understanding in an information retrieval dialogue system. There are described methods of use the finite state transducers for conceptual semantic parsing and meaning extraction from speaker's utterances. In this case, the main aim of understanding is the identification of important semantic constituents and their application dependent on the interpretation within the supposed frame structure. The key problem is to create an appropriate mapping between a sequence of the recognized words and a concept based on meaning that represents the real-world entities. We preferred for the given task to use a hierarchical stochastic language model principle rather than a linguistic rule based on parsing methods used in the natural language processing. The used approach is convenient particularly when the treated spoken language doesn't follow a standard grammar due to spontaneous speech phenomena and recognition errors.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi
Interventions for increasing medication adherence in heart failure patients: A narrative review
Heart failure is one of the critical and most costly medical challenges of the 21st century. It is a chronic debilitating condition and adherence to medication, a precondition for successful treatment is often poor. There are various interventions for improving the adherence. Depending on the goal of the intervention, these are roughly patient centric, healthcare provider centric and system centric. We provide an overview of these interventions with a focus on effectiveness and appropriateness in different clinical situations. Their use can lead to improved patient outcomes and reduced economic burden of the disease
