Search results for "material"
showing 10 items of 32550 documents
Multifunctional hybrid nanocomposites based on carbon nanotubes and chemically modified graphene
2013
La Tesis trata del desarrollo de materiales híbridos multifuncionales basados en nanotubos de carbono y grafeno con interés en magnetismo molecular y electrónica molecular This Thesis deals with the chemistry and development of new hybrid multifunctional systems based on carbon nanotubes (CNTs) and graphene (G). To introduce both types of carbon nanoforms a brief historical overview of these systems has been briefly given at the Preface. Next and prior to the presentation of the results, two introductory chapters in which the principal aspects of the synthesis, properties and applications of carbon nanotubes (chapter 1) and graphene (chapter 2) are given. The results have been divided in th…
Pb-PbOHCl Composite Nanowires Synthesized by Galvanic Deposition in Template
2019
In this paper, we report a detailed study on the synthesis of composite nanowires of Pb-PbOHCl via galvanic deposition into the pores of a membrane acting as a template. PbOHCl deposition quantitatively occurs as the solution pH exceeds the value of about 4.12. Simultaneously, owing to the galvanic coupling, electro-deposition of lead occurs, so composite nanowires were formed. The role of different parameters controlling the kinetic evolution of the process, such as oxygen bubbling, solution pH, surface area and type of sacrificial anode were investigated one at a time. The results suggest that every modification accelerating the alkalization of the solution inside the template pores favor…
Optical Properties of III-V Nanowires and Their Application for Charge Transport and Single-Photon Emission
2012
This work covers the optical characterization of III-V semiconductor nanowires and their application for charge transport and for single-photon emission. InAs nanowires have been investigated by Raman scattering and PL spectroscopy. The possibility to grow nanowires with a crystal structure different from its bulk counterpart has aroused a lot of interest in their optical and electronic properties. Here, the optical phonon modes of wurtzite InAs nanowires have been studied by polarized Raman scattering. For the first time, Raman measurements on a single InAs nanowire have revealed the A1(TO) and E2h optical phonon modes of the wurtzite structure. Additional resonant Raman scattering experim…
Elemental and microbiota content in indoor and outdoor air using recuperation unit filters
2021
Detection and quantification of engineered nanomaterials in environmental systems require precise knowledge of the elemental composition, association, and ratios in homologous natural nanomaterials (NNMs). Here, we characterized soil NNMs at the single particle level using single particle-inductively coupled plasma-time of flight-mass spectrometer (SP-ICP-TOF-MS) in order to identify the elemental purity, composition, associations, and ratios within NNMs. Elements naturally present as a major constituent in NNMs such as Ti, and Fe occurred predominantly as pure/single metals, whereas elements naturally present at trace levels in NNMs occurred predominantly as impure/multi-metal NNMs such as…
Comparison of different theory models and basis sets in the calculation of 13C NMR chemical shifts of natural products.
2004
The influence of the calculation method in mimicking experimental 13C NMR chemical shifts of 15 low-polarity natural products singularly containing 10–20 carbon atoms was investigated by employing different quantum chemistry approaches and basis sets, both in the preliminary geometry optimizations and in the following single-point 13C GIAO calculations of the NMR chemical shifts. The geometries of the involved species were optimized at the PM3, HF, B3LYP and mPW1PW91 levels whereas the 13C NMR parameters were determined at the HF, B3LYP and mPW1PW91 levels. Different combinations of basis sets were also tested. The consistency and efficiency of the considered combinations of geometry optimi…
Herbal Medications in Endodontics and Its Application—A Review of Literature
2022
Herbal products are gaining popularity in dental and medical practice nowadays due to their biocompatibility, higher antimicrobial activity, antioxidant and anti-inflammatory properties. Herbal medicine has experienced rapid growth in recent years due to its beneficial properties, ease of availability, and lack of side effects. As pathogenic bacteria become more resistant to antibiotics and chemotherapeutic agents, researchers are becoming more interested in alternative products and treatment choices for oral diseases. As a result, natural phytochemicals separated from plants and utilized in traditional medicine are suitable substitutes for synthetic chemicals. The aim of this review articl…
Le Clos de Vougeot (Côte-d’Or) : nouvelles observations sur les matériaux de construction et la chronologie du bâti médiéval
2009
Mithilfe sehr unterschiedlicherMethoden hat es sich diese Arbeit vor allem zur Aufgabe gemacht, bestimmte Phasen der Baugeschichte des Clos de Vougeot zu verstehen, um die Organisation und die Entwicklungen eines Zisterzienserhofsin Hinsicht auf diesozialen und historischen Wandlungen besser zu verstehen. Diese Studie bot ebenfalls Gelegenheit, die geologischen Eigenschaften der im Clos de Vougeot eingebrachten Baumaterialien genauestens zu untersuchen und neue Erkenntnisse zum Bau dieser Gebäude zu gewinnen und zu präzisieren.
Study of Intumescent Coatings Growth for Fire Retardant Systems in Naval Applications: Experimental Test and Mathematical Model
2022
Onboard ships, fire is one of the most dangerous events that can occur. For both military and commercial ships, fire risks are the most worrying; for this reason they have an important impact on the design of the vessel. The intumescent coatings react when heated or in contact with a living flame, and a multi-layered insulating structure grows up, protecting the underlying structure. In this concern, the aim of the paper is to evaluate the intumescent capacity of different composite coatings coupling synergistically modeling and experimental tests. In particular, the experiments have been carried out on a new paint formulation, developed by Colorificio Atria S.r.l., in which the active comp…
Mācību materiālu izveide militārās angļu valodas apguvēju mutvārdu saziņas veicināšanai
2019
Speciālo nozaru angļu valoda ir pieprasīta dažādu jomu speciālistu vidū, jo sniedz iespēju apgūt profesionālo angļu valodu. Šī pētījums mērķis bija noteikt militārās angļu valodas apguvēju individuālās valodas vajadzības un izveidot mācību materiālus, kas veicinātu viņu mutvārdu saziņu. Mācību materiāli tika izstrādāti, izmantojot uz uzdevumiem balstītu metodoloģiju, kas nodrošina valodas apguvi, izmantojot jēgpilnus uzdevumus, atbilstošus komunikatīvus vingrinājumus, lai veicināti valodas funkciju apguvi, kas nepieciešamas, lai attīstītu valodu tās lietojumam reālās situācijās. Pētījuma dati tika iegūti, izmantojot anketas, nodarbību novērošanu, un progresa testus, kas tika rūpīgi analizēt…
Towards Socio-material Research Approaches in Language Education
2022
AbstractThis chapter outlines the socio-material framing of the book that it opens. We situate this volume materially not only in the discipline of applied linguistics and language education, but also in the long tradition of applied language studies at the University of Jyväskylä in Finland and the community there. In doing so, the book builds on the authors’ roots in social constructionist thought and explicates why an orientation towards new materialism may be useful for a consideration of equity issues in language education. Socio-materialism fosters a critical, transformative perspective and encourages an ontological ethical grounding of research, thus providing a starting point for re…