Search results for "Generation"
showing 10 items of 3050 documents
Histological and histomorphometrical analysis of a silica matrix embedded nanocrystalline hydroxyapatite bone substitute using the subcutaneous impla…
2010
The clinical suitability of a bone substitute material is determined by the ability to induce a tissue reaction specific to its composition. The aim of this in vivo study was to analyze the tissue reaction to a silica matrix-embedded, nanocrystalline hydroxyapatite bone substitute. The subcutaneous implantation model in Wistar rats was chosen to assess the effect of silica degradation on the vascularization of the biomaterial and its biodegradation within a time period of 6 months. Already at day 10 after implantation, histomorphometrical analysis showed that the vascularization of the implantation bed reached its peak value compared to all other time points. Both vessel density and vascula…
An Investigation into the Stability of Graphitic C 3 N 4 as a Photocatalyst for CO 2 Reduction
2018
The increasing CO 2 concentration in the atmosphere exerts a significant influence on global warming and climate change. The capture and utilization of CO 2 by conversion to useful products is an area of active research. In this work, the photodriven reduction of CO 2 was investigated using graphitic carbon nitride (g-C 3 N 4 ) as a potential photocatalyst. The photocatalytic reduction of CO 2 was investigated with g-C 3 N 4 powder immobilized on a glass support in a batch gas-phase photoreactor. The experiments were carried out under UV-vis irradiation at 70 °C and an initial pressure of 2.5 bar. The only gas-phase product detected during the irradiation of the g-C 3 N 4 in the presence of…
Photosensitivity and second harmonic generation in chalcogenide arsenic sulfide poled glasses
2011
International audience; The present work investigates the photoinduced Second Harmonic Generation processes in thermally poled arsenic sulfide glasses. SHG Maker fringes patterns associated to SHG kinetic measurements about illumination and Raman spectroscopy have been conducted in order to bring new information which confirm the combined influence of charge carriers and mid-range glass structural modification on the poling and the photodarkening mechanisms.
Chalcogenide Glasses Based on Germanium Disulfide for Second Harmonic Generation
2007
International audience; High second-order susceptibilities are created by thermal poling in bulk germanium disulfide based chalcogenide glasses. Experimental conditions of the poling treatment (temperature, voltage, time) were optimized for each glass composition. The second-order nonlinear signals were recorded by using the Maker fringes experiment and a second-order coefficient χ(2) up to 8 pm V-1 was measured in the Ge25Sb10S65 glass. This value is obtained using a simulation based on accurate knowledge of the thickness of the nonlinear layer. Two mechanisms are proposed to explain the creation of a nonlinear layer under the anode: the formation and the migration of charged defects towar…
Nonlinear Disorder Mapping via Wave Mixing in poled Lithium Tantalate
2010
We introduce and test a simple approach for the characterization of domain distribution in bulk quadratic ferroelectric crystals, specifically periodically poled Lithium Tantalate with random mark-to space ratio.
Nonlinear Disorder Mapping via Three Wave Mixing in Poled Lithium Tantalate
2010
We introduce and test a simple approach for the characterization of domain distribution in bulk quadratic ferroelectric crystals, such as periodically poled Lithium Tantalate with random mark-to space ratio.
Structure-dependent tuning of electro-optic and thermoplastic properties in triphenyl groups containing molecular glasses
2015
Abstract The series of seven molecular compounds composed of D–π–A chromophores and triphenylmethyl auxiliary groups were characterized by UV–Vis spectroscopy, differential scanning calorimetry and quantum chemical calculations. Nonlinear optical (NLO) properties of compounds were determined by second harmonic generation measurements in corona poled thin glassy films. The results show that triphenylmethyl auxiliary groups are effective at shielding undesirable dipole interactions in solid phase thus increasing NLO efficiency of materials. Thermal stability up to 108 °C was achieved for a polar order in poled samples.
Thermoeletric Heusler Compounds
2015
Thermoelectric converters for power generation aim at reducing CO\(_2\) emission via the conversion of a part of the low-grade waste heat generated by engines, industrial furnaces, gas pipes, etc. to electricity. The recovery of waste heat from the exhaust of an automotive engine, in particular, is an attractive, albeit not very efficient way for reduction of fuel consumption. Thermoelectric converters with high overall efficiency convert heat directly into electricity without moving parts and, thus, not only decrease our reliance on fossil fuels but also actively counteract global warming. State-of-the-art converters are simply too inefficient to be economic, partly due to expensive elemen…
Performance Enhancement of Alkaline Water Electrolyzer Using Nanostructured Electrodes Synthetized by Template Electrosynthesis
2018
The increase of power generation by renewable sources is causing problems in the management of the electricity grid. In order to favor the transition from the current energy production towards renewable energy sources, it is necessary to plan strategy to develop suitable energy storage systems. Certainly, the electrochemical hydrogen production can be considered as one of the most promising storage technologies. In this work, an innovative alkaline electrolyzer is presented from its design based on the use of nanostructured electrodes up to its implementation suggested by the results of tests simulating real operation. The nanostructured electrodes were fabricated by template electrosynthes…
All-organic electro-optic waveguide modulator comprising SU-8 and nonlinear optical polymer
2017
Institute of Solid State Physics, University of Latvia (SJZ/2016/26); Ministry of Education and Science, Republic of Latvia (MultIfunctional Materials and composItes, photonicS and nanotechnology (IMIS2)). We acknowledge Dr. Anatolijs Sarakovskis at Institute of Solid State Physics for the XPS measurements.