Search results for "SAND"

ANALISI DEL COMPORTAMENTO MECCANICO DI SANDWICHES GREEN COSTITUITI DA PELLI IN BIOCOMPOSITO E CORE IN BALSA/SUGHERO

2022

Negli ultimi anni l’aumento della sensibilità nei confronti della salvaguardia ambientale, anche attraverso apposite norme in materia di lotta all’inquinamento e di riciclo dei materiali a fine vita, ha portato ad un notevole interesse dei ricercatori verso i cosiddetti compositi green, materiali costituiti in genere da rinforzi di origine naturale e matrici “bio-based” a basso impatto ambientale. Una categoria interessante di materiali innovativi, caratterizzati da una elevata resistenza a flessione unita ad un basso peso specifico, è rappresentata dai cosiddetti sandwiches, costituiti in genere da robuste pelli in composito fibro-rinforzato e da un core in materiale molto leggero e poco r…

Electroosmotic effects in the determination of ion mobilities of carrier-free radionuclides in free aqueous electrolyte solutions

2001

A device for on-line electromigration studies of radio-elements in free electrolytes has been tested by measuring the absolute individual ion mobilities of no-carrier-added single charged anions [99mTc]TcO4 - and [18F]F- and differently charged cations [137Cs]Cs+, [57Co]Co2+ and [241Am]Am3+ in inert aqueous electrolytes at 298.1 K. The observed ion mobilities were found to be influenced by electroosmosis in the migration tube. A relation to correct this effect is proposed. In addition, it was shown that the effect of electroosmosis may be suppressed by chemical treatment of the surface of the migration tube.

"Paroles de femmes pour la liberté : Georges Sand, Veuillez être leurs égales (avril 1848)"

2013

DESIGNING A TEACHER TRAINING PROGRAMME FOR CHARACTER EDUCATION: AN INTERNATIONAL PARTNERSHIP

2020

There is a need of innovative teacher training programmes for character education. This paper addresses three research questions: What are the challenges that a teacher training programme for character education should address? What are the learning outcomes that the programme should achieve? How should the programme be structured for supporting the achievement of those learning outcomes? Two regional authorities, three schools, three universities and a centre of teacher training from Latvia, Estonia and Spain created a strategic partnership for answering these research questions, using design-based implementation research. The results include six domains of learning outcomes and a programm…

Modeller i kjemiundervisning - et eksempel på hvordan de kan bidra til læring og feillæring

2021

We discuss the use of analogical models in science education using examples from online learning resources.  We have conducted a teaching program for a group of 7th grade pupils and a group of science teacher students, and the main theme of this program is the use of models in chemistry. Specifically, we study the effect of an analogical model that is designed to promote understanding of the properties of molecules, related to a paper chromatography experiment. Our research indicates that analogical models can be a useful tool to convey understanding of abstract concepts and non-visible phenomena, but they hold serious pitfalls that can lead to misunderstandings amongst students if not used…

Iron(II) complexes of naphthalenes. X-ray structure of [cyclopentadienyl-iron(II)-η6-octamethylnaphthalene]PF6

1992

Abstract Complex ions [cyclopentadienyl-Fe(methylnaphthalene)]+ with 4 to 8 methyl substituents have been prepared from [CpFe(o-dichlorobenzene)]+ by a photochemical ligand exchange. Complexation shifts have been determined for 1H and 13C resonances of the η6-bonded naphthalenes. The X-ray structure of [CpFe(octamethylnaphthalene)]PF6 0.5 acetone has been determined. Crystals are monoclinic, the space group C2/c with unit-cell dimensions a = 10.689(4), b = 22.391(5), c = 20.550(4)A, β = 93.41(2)°, Z = 8. The structure determination established a distorted molecular geometry of the octamethylnaphthalene that is different from the free arene and its Cr(CO)3 complex.

Challenges in Information Systems Procurement in the Norwegian Public Sector

2011

Published version of a chapter in the book Lecture Notes in Computer Science, 6846, 404-417. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-642-22878-0_34 Public procurement of information systems (IS) and IS services provides several challenges to the stakeholders involved in the procurement processes. This paper reports initial results from a Delphi study, which involved 46 experienced procurement managers, chief information officers, and vendor representatives in the Norwegian public sector. The participants identified altogether 98 challenges related to IS procurement, divided further into 13 categories: requirements specification, change management, cooperation a…

Catastrophic effects of sand mining on macroinvertebrates in a large shallow lake with implications for management

2019

Sand mining is a human activity that is increasing in inland waters and has profound effects on entire aquatic ecosystems. However, current knowledge of the effects of sand mining on freshwater lake ecosystems remains limited, especially for biotic communities. Here, we investigated the responses of macroinvertebrates to indiscriminate sand mining in a large shallow lake of China. Our results indicated that sand mining significantly increased the content of suspended particulate matter, total nitrogen, total phosphorus and chlorophyll a in the water column both in the sand mining area and the area adjacent to the dredging activities. While there was significantly lower total nitrogen and th…

Experimental and theoretical characterization of the strong effects on DNA stability caused by half-sandwich Ru(II) and Ir(III) bearing thiabendazole…

2020

Abstract: The synthesis and characterization of two half-sandwich complexes of Ru(II) and Ir(III) with thiabendazole as ancillary ligand and their DNA binding ability were investigated using experimental and computational methods. 1H NMR and acid–base studies have shown that aquo-complexes are the reactive species. Kinetic studies show that both complexes bind covalently to DNA through the metal site and non covalently through the ancillary ligand. Thermal stability studies, viscosity, circular dichroism measurements and quantum chemical calculations have shown that the covalent binding causes breaking of the H-bonding between base pairs, bringing about DNA denaturation and compaction. Addi…

Multimodale Analyse von Interaktion im fremdsprachlichen Klassenzimmer. Multimodal analysis of interaction in a foreign language class.

2016

The article offers a contribution to the interaction research in the foreign language teaching and learning. It starts with an overview of various research approaches to the foreign language teaching and learning, from the 60s to the present days. A multimodal analysis of an excerpt of videorecorded classroom interaction is then provided. The analysis is focused on several aspects of classroom participation and teaching sequences. Some implications of the present research for teachers' training are finally provided.