Search results for "element"
showing 10 items of 13601 documents
A Computational Study of Adsorption of CO2, SO2, and H2CO on Free-Standing and Molybdenum-Supported CaO Films
2018
Oxide films play a significant role in a wide range of fields from catalysis to solar cell materials. CaO films are promising sorbents for many environmentally harmful molecules. Here, we report a systematic investigation of adsorption of CO2, SO2, and H2CO on bulk and Mo-supported CaO(100) films using density functional theory. Significant effects on adsorption energy, charge transfer to the molecules, and degree of the C–O bond activation were demonstrated on Mo-supported CaO films by changing the film thickness, composition, and the strength and direction of an applied external electric field. These findings are relevant for interpreting results from scanning tunneling microscopy of smal…
Mathematical modelling of sustainable bioresidual concrete
2019
In the production of cement, which is the main component of concrete production, the process generates about 5% of the global carbon dioxide emissions. In addition, bioproduct and pulp mills produce signi_cant quantities of soda ash and bio-ash, which is still largely unused. In this paper we will introduce our study related to improving the environmental friendliness of concrete used in construction by utilizing pulp mill waste while its long-term durability and strength and porosity properties meet the goals set for construction. The project `sustainable bioresidual concrete' is on-going and only preliminary numerical results with measurements are presented here. peerReviewed
Narrative inquiry and historical skills. A study in teacher training
2017
This paper addresses narrative thinking and literacy levels in future primary school teachers in Spain. It uses the study of a historical synthesis of one of the main narratives in Spanish history: the Christian expansion through Muslim territories in the Iberian Peninsula in the Middle Ages. Accounts by 283 students of the degree in elementary school teaching at the universities of Valencia and Murcia were studied. The aim was to ascertain the students' discursive abilities with respect to their historical thinking skills. The results reveal poor narrative skills in future teachers and a very low level of historical literacy.
Il bugnato a punta di diamante in Sicilia tra XV e XVI secolo
2009
Diamond shaped bosses in 15th and 16th century in Sicily Diamond shaped bosses are to be found in many Sicilian buildings dating from the 15th and 16th centuries, whether as a means of covering extensive surfaces or, not less significantly, as a decorative element in doorways, windows and niches inside the spandrels supporting domes, both in religious and civil architecture. This study takes into account certain stylistic and constructive aspects in a number of buildings, such as the shape and dimension of the pieces, the way they are placed, the materials employed; these details, together with the dates of construction, make it possible to observe differences and similarities, and (especia…
Latvijas sabiedrības viedoklis par homoseksualitāti atainojošu elementu iekļaušanu uzņēmumu reklāmās kampaņu komunikācijā Latvijā
2022
Maģistra darba mērķis ir noskaidrot, kāds ir Latvijas sabiedrības viedoklis par homoseksualitāti un homoseksualitātes atainojošu elementu iekļaušanu uzņēmumu reklāmās kampaņu komunikācijā Latvijā. Pētījuma teorētiskā daļa sastāv no tādām teorijām kā mediju efektu teorija un sociālās mācīšanās teorija. Papildus iekļauta teorija par homoseksualitāti un tās sasaisti ar reklāmu. Pētījuma rezultāti iegūti, veicot aptaujas anketas izstrādi un izplatīšanu, veicot fokusa grupas interviju un realizējot daļēji strukturētu interviju ar Latvijas Reklāmas Asociācijas valdes priekšsēdētāju Baibu Liepiņu. Veicot fokusa grupas diskusiju, tās pamatā tiek izmantota mediju efektu teorija, pētot cilvēku izziņa…
Lifestyle influence on trace element contents in human scalp hair of young residents in different urban contexts. Preliminary results.
2010
A causal relationship between earth material and human health, although not always proven, is highly plausible because many chemical elements in rocks and soils are directly inhaled by respiration or transmitted, via air, water and vegetation, into food chain and then to human body. It is well known that metals and metalloids may result essential to biochemical and physiological functions, but it is also well known that health problems may derive from either dietary deficiencies or excesses. Among the techniques employed to assess the exposure of living organisms to metals and metalloids present in the environment, the human biomonitoring has attracted the attention of investigators over th…
Aqueous-phase reactive species formed by fine particulate matter from remote forests and polluted urban air
2021
In the aqueous phase, fine particulate matter can form reactive species (RS) that influence the aging, properties, and health effects of atmospheric aerosols. In this study, we explore the RS yields of aerosol samples from a remote forest (Hyytiälä, Finland) and polluted urban locations (Mainz, Germany; Beijing, China), and we relate the RS yields to different chemical constituents and reaction mechanisms. Ultra-high-resolution mass spectrometry was used to characterize organic aerosol composition, electron paramagnetic resonance (EPR) spectroscopy with a spin-trapping technique was applied to determine the concentrations of ⚫OH, O2⚫-, and carbon- or oxygen-centered organic radicals, and a …
Short-term effects of potassium fertilization on the hydraulic conductance of Laurus nobilis L.
2011
This study reports experimental evidence on the effect of short term potassium fertilization on potassium uptake, tissue concentration and hydraulic conductance of pot-grown laurel plants. Potassium uptake and loading into the xylem of laurel seedlings increased within 24 h from fertilization. Potassium was not accumulated in roots and leaves, but the [K+] of xylem sap was 80% higher in fertilized plants (+K) than in potassium starved plants (-K), likely as a result of recirculation between xylem and phloem. This increase in xylem sap [K+] resulted in a 45% increase in transpiration rate, a 30% increase in plant hydraulic conductance (Kplant) and a 120% increase in leaf specific conductivit…
Crystal structure and Hirshfeld surface analysis of (2E)-3-(3-bromo-4-fluorophenyl)-1-(3,4-dimethoxyphenyl)prop-2-en-1-one
2018
The title compound is constructed from two aromatic rings (3-bromo-4-fluorophenyl and 3,4-dimethoxyphenyl), which are linked by a C=C—C(=O)—C enone bridge and form a dihedral angle of 17.91 (17)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds enclosing rings of (14) graph-set motif to form layers parallel to (10).
Role of elastic and electronic interactions in trapping of hydrogen by impurities in transition metals
1985
The interplay between the lattice distortion and the electronic contributions to the trapping of migrating hydrogen isotopes by substitutional impurities is investigated. We use a comprehensive calculational scheme incorporating (i) the effective-medium theory for the electronic interaction, (ii) the lattice Green’s function for elastic coupling, and (iii) the hydrogen quantum motion. The calculations for Ti and Cr impurities in V host show that lattice strain effects dominate. Cr, which otherwise provides an electronic trap site, does not induce trapping when elastic effects are incorporated. The situation in the case of Ti is just the reverse. We find no isotope dependence of the binding …