Search results for "THERMAL"
showing 10 items of 3576 documents
The effect of the internal architecture of polymer micronetwork colloids on the dynamics in highly concentrated dispersions
2007
Motivated by the finding that colloidal dispersions of polymer micronetwork spheres with a cross-link density of 1:50 (inverse number of monomer units between crosslinks) show significant deviations from the dynamics of hard spheres in the colloid glass as seen by dynamic light scattering (DLS) (E. Bartsch, V. Frenz, H. Sillescu J. Non — Cryst. Solids 172–174 (1994), 88–97), we have undertaken a systematic study of the effect of the crosslink density on the dynamics at high concentrations. Long-time self-diffusion coefficients D S L and collective diffusion coefficients D c were measured for colloids with crosslink densities of 1:10, 1:20 and 1:50 by forced Rayleigh scattering (FRS) and the…
Thermal solitons in nanotubes
2022
Starting from a recent proposal of a nonlinear Maxwell-Cattaneo equation for the heat transport with relaxational effects at nanoscale, in a special case of thermal-wave propagation we derive a nonlinear Schrodinger equation for the amplitudes of the heatflux perturbation. The complete integrability of the obtained equation is investigated in order to prove the existence of infinite conservation laws, as well as the existence of infinite exact solutions. In this regards, we have considered the simplest nontrivial solutions, namely, the bright and dark (thermal) solitons, which may be interesting for energy transport and for information transmission in phononic circuits. (c) 2022 Elsevier B.…
A Comprehensive Thermogravimetric Analysis Multifaceted Method for the Exact Determination of the Composition of Multifunctional Metal‐Organic Framew…
2020
Thermogravimetric analysis (TGA) has been widely used as a tool to characterise the composition of materials such as Metal-Organic Frameworks (MOFs). However, given their multifunctionality and structural complexity, examples of detailed methodologies for the exact calculation of the composition of complex MOF structures and MOF composites are lacking in the literature. Herein, we introduce a new straightforward methodology – based on the experimental ratio between the mass of a structure and its residue – for the exact calculation of the composition of almost any MOF material. We provide a detailed guide for the application of our methodology to different MOF materials, including MOFs in w…
Suitability of Illite Based Clays of Latvia for Chemical and Thermal Activation
2014
Materials has been synthesized in the temperature range from 600-800 0C from illite based clays of Latvia under activation of KOH and NaOH solutions (4-6 M). Compressive strength and apparent porosity were measured. The effect of the concentration of KOH and NaOH solutions on the material mechanical properties was investigated by means of infrared spectroscopy (IR). Compressive strength data of the materials showed that via such activation building materials with good quality can be obtained.
ChemInform Abstract: Evidence for the Formation of 1,3- and 1,4-Dehydrobenzenes in the Thermal Decomposition of Diaryliodonium-carboxylates.
1987
Abstract Abstract: Generation of m- and p-benzynes in decomposition of diaryliodonium- 3- and 4-carboxylates is demonstrated by three-phase method.
HTLS Conductors: A Way to Optimize RES Generation and to Improve the Competitiveness of the Electrical Market—A Case Study in Sicily
2018
Stringent environmental constraints make more difficult to identify new energy corridors and build new power lines. The increase in the generation of electricity from renewable energy sources (RESs) makes the operation of electrical systems increasingly difficult in some areas. The transmission system operators (TSOs), in Italy Terna, are forced to exploit the existing overhead transmission lines, increasing the possibility of dispatching energy, in particular RES, optimizing the transmission capacity. Therefore, after a brief presentation of the Sicilian electricity system and a brief description of high-temperature low-sag (HTLS) conductors, a case study is presented. It is shown how it i…
A review of thermochemical energy storage systems for power grid support
2020
Power systems in the future are expected to be characterized by an increasing penetration of renewable energy sources systems. To achieve the ambitious goals of the “clean energy transition”, energy storage is a key factor, needed in power system design and operation as well as power-to-heat, allowing more flexibility linking the power networks and the heating/cooling demands. Thermochemical systems coupled to power-to-heat are receiving an increasing attention due to their better performance in comparison with sensible and latent heat storage technologies, in particular, in terms of storage time dynamics and energy density. In this work, a comprehensive review of the state of art of theore…
Energy Conscious Building Design
1987
Since the beginning of energy crisis many design tools have been developed in order to enable the designer to cope with energy consumption in buildings. These tools are of different kind: from very sophisticated simulation models to simplified (often too much) methods. Each of them offers various advantages and disadvantages, and it is up to the designer to choose among them.
Thermal simulation of a power transformer
2019
In the article we propose a method of thermally constructive optimization of a 110/20 kV power transformer by numerical simulation (by the finite element method) of the thermal field in the transformer. The thermal simulation was done in the Comsol module called Heat Transfer Module, based on the documentation in Catia V5, and the experimental validation was done by thermography.
Experimental and Numerical Analysis of Air Flow, Heat Transfer and Thermal Comfort in Buildings with Different Heating Systems
2016
Abstract Monitoring of temperature, humidity and air flow velocity is performed in 5 experimental buildings with the inner size of 3×3×3 m3 located in Riga, Latvia. The buildings are equipped with different heating systems, such as an air-air heat pump, air-water heat pump, capillary heating mat on the ceiling and electric heater. Numerical simulation of air flow and heat transfer by convection, conduction and radiation is carried out using OpenFOAM software and compared with experimental data. Results are analysed regarding the temperature and air flow distribution as well as thermal comfort.