Search results for "DF"
showing 10 items of 1699 documents
Calculation of magnetic coupling constants with hybrid density functionals
2013
The currently available computational methods for the calculation of magnetic coupling constants with density functional theory have been reviewed. These methods include modern approximations to the exchangecorrelation functional, such as hybrid, range-separated and double-hybrid functionals, as well as approaches to treat the severe spin symmetry problems encountered in density functional calculations of magnetic interactions. In addition to the commonly used unrestricted Kohn–Sham formalism, density functional methods based on multireference wave functions and ensemble densities are also discussed. Performance of these models based on various studies has been summarized. The results indic…
Semanttiset verkot ja niiden web-sovellukset
2003
Semanttiset verkot ovat formalismeja tietämyksen esittämiseen. Semanttisia verkkoja on sovellettu asiantuntijajärjestelmissä, luonnollisen kielen käsittelyssä ja muissa tekoälyä hyödyntävissä sovelluksissa. Semanttinen web on joukko teknologioita, joiden tarkoitus on saada WWW:n sisältö ja merkitykset helpommin tietokoneen ymmärrettävään muotoon. Tutkielma selvittää semanttisen webin suhdetta olemassaoleviin tietämystekniikan sovelluksiin erityisesti semanttisten verkkojen näkökulmasta.
Influence of Distance from the Host on Parasitisation by
2019
The olive fruit fly, Bactrocera oleae, is considered the main olive pest worldwide, and has been the target of biological control programmes through the release of the braconid parasitoid Psyttalia concolor. Laboratory tests were performed to evaluate the influence of distance from the host on parasitisation, placing larvae of the substitute host Ceratitis capitata at seven distances (0, 0.5, 1, 1.5, 2, 2.5, 3 mm) and four different time periods (7, 15, 30, 60 min). Moreover, field collected olives of Ogliarola Barese cultivar infested by B. oleae were exposed to P. concolor females to confirm its ability to parasitise B. oleae in small olives. Psyttalia concolor oviposition was inhibited a…
Laika perspektīvas, apzinātības un apzinātības prakses saistības
2017
Pētījums “Laika perspektīvas, apzinātības un apzinātības prakses saistība” ir veltīts laika perspektīvas un apzinātības saistībai, kā arī pārmaiņām, pēc apzinātības prakses. Pētījumā piedalījās 66 respondenti, vecumā no 18 līdz 28 gadiem. Pētījumā tika izmantotās Apzinātības piecu aspektu aptauja (Five Facet Mindfulness Scale, Baer, Smith, Hopkins, Krietmeyer, Toney, 2006), un Zimbardo laika perspektīvas aptauja (Zimbardo Time Perspective Inventory, Zimbardo & Boyd, 1999). Noskaidrots, ka zems apzinātības līmenis var būt saistīts ar negatīvu orientāciju uz pagātni (rs=-0,48, p<0,005), fatālistisku attieksmi pret tagadni (rs=-0,33, p<0,005). Atkārtotā mērījuma dati parāda, ka apzinātības pra…
MODELLING BIOGAS GENERATION AND RELEASE FROM MUNICIPAL SOLID WASTE LANDFILLS
2015
MSW sanitary landfills represent nowadays one of the most important issue related to the waste management cycle. In particular, knowledge about biogas production is a key aspect for a proper exploitation of this energy source, even in the after-care phase. In the present study, a simple mathematical model was proposed for the simulation of biogas production. The model is based on 1st order biodegradation kinetic and takes also into account the temperature variation in time and depth and the landfill settlement. The model was applied to a real landfill located in Sicily (ITALY) and its simulation result was compared with experimental data (volumes of biogas collected by the recovery system a…
DEVELOPMENT TRENDS OF BIOGAS
2015
All over the world, researches are made in order to improve the technologies, the operational and process stability and performance of biogas plants, because the world markets for biogas increased considerably in Europe and all over the world. In this paper we studied the most important parameters related to a biogas plant, starting from the ecologic landfill of Cristian, Sibiu, a landfill which storages industrial and household waste. In this respect, we studied operational parameters, such as organic load and hydraulic retention time, and parameters for evaluation of a biogas plant. Also, we made a case study concerning the evaluation of used waters in the landfill described above under t…
Direct detection of 17O NMR in [Gd(DOTA)]- by NMR Spectroscopy
2015
The 17O NMR spectrum of the non-coordinated carboxyl oxygen in the GdIII-DOTA (DOTA = tetraazacyclododecanetetraacetic acid) complex has been observed experimentally. Its line width is essentially unaffected by paramagnetic relaxation due to gadolinium, and is only affected by the quadrupole pathway. The results are supported by the relevant parameters (hyperfine and quadrupole coupling constants) calculated by relativistic DFT methods. This finding opens up new avenues for investigating the structure and reactivity of paramagnetic GdIII complexes used as contrast agents in magnetic resonance imaging.
Structural and electronic properties of ion-exchangeable layered perovskites
2013
The modification of metal oxide surfaces with organic moieties has been widely studied as a method of preparing organic-inorganic hybrid materials for various applications. Among inorganic oxides, the ion-exchangeable layered perovskites, materials composed by perovskite-like slabs (ABO3, in which B is a small transition metal cation and A is a larger s-, d- or f-block cation) and intercalated cations, stimulated authors’ interest in reason of some encouraging electronic and reactive properties. In particular it is well known that the interlayer surface of layered-perovskites in their protonated form can be easily functionalized with organic groups, such as alcohols, organophosphonic acids,…
Yoga en España. Proceso de regulación profesional
2015
New approaches to spirituality go hand in hand with emerging physical, psychological and spiritual movements that have had a clear impact on many areas, and in particular on health and well-being. It is increasingly common to find nurses teaching yoga or doctors prescribing mindfulness. Use of socalled Complementary and Alternative Medicine (CAM) is becoming mainstream. Health centres, medical practices and even schools are offering a growing number of alternative therapies, resulting in the need for effective legal regulation of these activities, both in terms of professional recognition and training. In Spain, recent legislation represents a significant breakthrough in the regulation of y…
Sustainable financing through crowdfunding
2019
The phenomenon of crowdfunding has been widely studied, while the sustainability of crowdfunded ventures is attracting growing interest from academia and society. In light of this interest, we conducted bibliometric analysis to study the relationship between crowdfunding and crowdfunded ventures&rsquo