Search results for "COMPOSITI"

Effect of doping and crystallite size on the electrochemical performance of Li4Ti5O12

2016

Defect spinel phase lithium titanate (Li4Ti5O12) has been suggested as a promising negative electrode material for next generation lithium ion batteries. Flame spray pyrolysis has been shown to be a viable fast, one-step process for synthesis of nanoparticulate Li4Ti5O12. However, due to the rapid quenching that is integral to the process the crystallite size remain very small and non-uniform. To overcome this shortcoming a vertical flow tube furnace was used to increase the high-temperature residence time. This resulted in an increase in the crystallite size and crystallinity of the product. As a result of this increase the electrochemical performance of the Li4Ti5O12 was markedly improved…

Study of the Effect of Two Phases in Li4SiO4–Li2SiO3 Ceramics on the Strength and Thermophysical Parameters

2022

This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (No. BR11765580). The research of the team from Latvia (A.M., V.P. and A.I.P.) has been carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the European Commission can be held responsible for them. The research was partly (A.M., V.P. and A.I.P.) performed in …

Phytochemical profile and phototoxicity of eleven Hypericum species extracts

2017

The genus Hypericum (family Hypericaceae) contains 484 species, one of which, Hypericum perforatum, is largely used in medicine as antidepressant, as well as antinflammatory, and antimicrobial agent. Hypericin, together with the other naphthodianthrone derivatives named hypericins (the red pigments recognized as partially responsible for biological activities of this plant), has been identified largely in more than 300 Hypericum species (Skalkos et al., 2006). Particularly, hypericins are one of the most potent naturally occurring photodynamic agents; indeed, upon light irradiation, they very effectively induce apoptosis and/or necrosis of cancer cells (Karioti et al., 2010) and thus might …

Assessment of Physical and Chemical Stability of Different Magnesium Compounds in Tablets

2020

Modern lifestyle, excessive chemicalization of agricultural products, excessive processing and refining of food, cause a decrease in daily intake of magnesium, cation with an extremely important role in prevention and treatment of many diseases. As a result, there arises the need for extra magnesium intake in the form of dietary supplements. In this study were evaluated the physical and chemical stability of magnesium-containing tablets, depending on the active compound and the excipients used. Magnesium tablets in the form of orotate, lactate, citrate, oxide and hydroxide were taken into study and physical and chemical stability were observed over the validity period, at 6 and at 12 month…

Solar UV radiation and plant responses : assessing the methodological problems in research concerning stratospheric ozone depletion

2010

Kohn-Sham Decomposition in Real-Time Time-Dependent Density-Functional Theory An Efficient Tool for Analyzing Plasmonic Excitations

2017

The real-time-propagation formulation of time-dependent density-functional theory (RT-TDDFT) is an efficient method for modeling the optical response of molecules and nanoparticles. Compared to the widely adopted linear-response TDDFT approaches based on, e.g., the Casida equations, RT-TDDFT appears, however, lacking efficient analysis methods. This applies in particular to a decomposition of the response in the basis of the underlying single-electron states. In this work, we overcome this limitation by developing an analysis method for obtaining the Kohn-Sham electron-hole decomposition in RT-TDDFT. We demonstrate the equivalence between the developed method and the Casida approach by a be…

Apparent and quantitative loss of fatty acids and triacylglycerols at frying temperatures

2012

[EN]: Olive and sunflower oils were heated at 180 °C for 5, 10 and 15 hours with the aim of defining the changes in the contents of fatty acid methyl esters (FAME) and triacylglycerols (TAG) under frying conditions. Differences between apparent and real loss of FAME or TAG are defined for an adequate interpretation of the changes taking place at high temperature. Such differences depend on the expression of the results and frequently result in erroneous conclusions. Results showed that from the normalized composition it could be deduced that only the most unsaturated FAME (C18:2) or TAG containing it was significantly altered. However, quantitative data indicated that all the unsaturated FA…

Technological change, occupational composition, and wage premiums : evidence from linked employer-employee data

2010

Nanocompositi ad elevata resistenza termo-ossidativa a base di poliammide e nano-argille multifunzionali

2014

Preparazione e caratterizzazione di nanocompositi strutturali costituiti da poliammide e carbonio nanostrutturato

2014

L’obiettivo della presente tesi di dottorato è stato la preparazione e la caratterizzazione di nanocompositi a matrice polimerica contenenti forme allotropiche del carbonio nanostrutturato; tali materiali, grazie alle particolari caratteristiche meccaniche e di rinforzo, trovano applicazione nella fabbricazione di speciali dispositivi individuali come guanti, elmetti, corpetti, etc... Sono state preparate fibre di poliammide (PA) contenenti carbon black (CB), nanoplacchette di grafite (GNP) e nanotubi di carbonio (CNT); per questi ultimi sono stati valutati, inoltre, gli effetti delle loro dimensioni e della funzionalizzazione della loro superficie sulle proprietà di rinforzo dei nanocompos…