Search results for "Method"
showing 10 items of 13253 documents
Actual and Potential Pedagogical Use of Tablets in Schools
2013
This study reviews the potential of tablet technology for teaching and learning. In autumn 2012, we conducted a focused survey comprising quantitative and qualitative questions with Finnish teachers (N = 171, from 54 schools). We focused on perceived pedagogical opportunities and the actualized pedagogical potential of tablets at schools. The survey results indicate that the actual usefulness of tablets in schools was significantly less than what teachers perceived as the pedagogical potential. However, the results demonstrate the positive impact these devices are having on teaching and learning, as well as prompting changes in pedagogical perspectives. Teachers stated that tablets can dive…
Graphitically encapsulated cobalt nanocrystal assemblies
2010
Graphitically encapsulated cobalt nanocrystal assemblies are chemically prepared by one-pot reaction at380 degrees C followed by a reversed etching process to produce porous graphitic structure for revealing their self-assembling nature.
DFT modelling of oxygen adsorption on the Ag-doped LaMnO3 (001) surface
2019
This study was partly financed by the State Education Development Agency of the Republic of Latvia via the Latvian State Scholarship (A.A.) and Latvia-Ukraine Project (Grant LV-UA/2018/2 to E.K.). The work of T.I. is performed under the state assignment of IGM SB RAS. Also, this research was partly supported by the Ministry of Education and Science of the Republic of Kazakhstan in the framework of the scientific and technology Program BR05236795 ‘‘Development of Hydrogen Energy Technologies in the Republic of Kazakhstan’’. The authors thank M. Sokolov for technical assistance and valuable suggestions.
EPR/ALANINE PELLETS WITH LOW Gd CONTENT FOR NEUTRON DOSIMETRY
2013
This paper reports on results obtained by electron paramagnetic resonance (EPR) measurements and Monte Carlo (MC) simulation on a blend of alanine added with low content of gadolinium oxide (5 % by weight) to improve the sensitivity to thermal neutron without excessively affecting tissue equivalence. The sensitivity is enhanced by this doping procedure of more an order of magnitude. The results are compared with those obtained with the addition of boric acid (50 % by weight) where boron is in its natural isotopic composition in order to produce low-cost EPR dosemeters. The gadolinium addition influences neutron sensitivity more than the boron addition. The presence of additives does not sub…
Laboratory measurements and astronomical search for the HSO radical
2016
[Context] Despite the fact that many sulfur-bearing molecules, ranging from simple diatomic species up to astronomical complex molecules, have been detected in the interstellar medium, the sulfur chemistry in space is largely unknown and a depletion in the abundance of S-containing species has been observed in the cold, dense interstellar medium. The chemical form of the missing sulfur has yet to be identified.
THE OCCURRENCE OF CHROMIUM IN RAW MATERIALS AND ITS FATE IN THE BREWING PROCESS
1987
The chromium content of raw materials, intermediate and final products in the brewing process were determined in order to evaluate the contribution of raw materials to the chromium content of beer. The contribution due to beer in the diet is considered in the light of the recommended daily intake of chromium.
Monte Carlo Simulations of Parallel Charged Platelets as an Approach to Tactoid Formation in Clay
2013
The free energy of interaction between parallel charged platelets with divalent counterions has been calculated using Monte Carlo simulations to investigate the electrostatic effects on aggregation. The platelets are primarily intended to represent clay particles. With divalent counterions, the free energy for two platelets or two tactoids (clusters of parallel platelets) shows a minimum at a short separation due to the attraction caused by ion-ion correlations. In a salt-free system, the free energy of interaction has a long-range repulsive tail beyond the minimum. The repulsion increases for tactoids with larger aggregation numbers, whereas the depth of the free-energy minimum is graduall…
Characterization of a Double Metal Cyanide (DMC)-Type Catalyst in the Polyoxypropylation Process: Effects of Catalyst Concentration
2014
The alkaline catalysts commonly applied to alkoxylation are characterized by a limited spectrum of activity caused by an irreversible termination of the polyether chains. The presented results show that double metal cyanide (DMC) catalysts reduce or eliminate the aforementioned adverse rearrangement of hydroxyl groups. Moreover, DMC catalysts indicate high activity at low concentrations (ppm range), as expressed by high polymerization rates. It was demonstrated that decreased concentrations of DMC catalyst irreversibly influence its reactivity and the dispersity of the obtained products, as exemplified by the production and determination of selected polyoxypropylenediols at different concen…
Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate
2020
AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen pero…
Self-Efficacy Between Previous and Current Mathematics Performance of Undergraduate Students: An Instrumental Variable Approach to Exposing a Causal …
2021
PurposeSelf-efficacy has been argued theoretically and shown empirically to be an essential construct for students’ improved learning outcomes. However, there is a dearth of studies on its causal effects on performance in mathematics among university students. Meanwhile, it will be erroneous to assume that results from other fields of studies generalize to mathematics learning due to the task-specificity of the construct. As such, attempts are made in the present study to provide evidence for a causal relationship between self-efficacy and performance with a focus on engineering students following a mathematics course at a Norwegian university.MethodThe adopted research design in the presen…