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Abstract  

The reproducibility of the phase changes at 533–543, 573–593K and 603–623 K in the system CuCl2−KCl was investigated by DTA analysis, supplemented with röntgenographic analysis. Conclusions were drawn in connection with a liquid melt and the solid state of the system.

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With a complex of physico-chemical methods for analysis it is proved that in the course of mechanochemical treatment of a Syrian phosphorite and ammonium sulphate mixture new phases have been formed. The thermal analysis proves an increase in the reaction properties of the ammonium sulphate and the Syrian phosphorite which is a prerequisite for the increase in the content of P2O5 assimilated , in the activated phosphorite mixtures and the possibility to use them in the production of NP complex fertilizers.

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/paraffin increased with the mass fraction of Al 2 O 3 nanoparticles. Hong et al. [ 15 ] added the encapsulated phase-change nanoparticles into a single-phase liquid to enhance its heat transfer property. It showed that the heat-transfer coefficients of

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. During the material phase change from solid to liquid or from liquid to gases, some heated energy will be absorbed for storage and vice versa. Two main components are required to utilize solar energy: collector units and storage units. Both components are

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Introduction The energy deficiency and environmental pollution during the energy utilization prompt the utilization of clean energy, such as solar, wind, and cheap power. The energy storage technology with phase change material

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latent heat of melting, is a promising kind of high temperature phase change materials. Basic thermo physical properties of nitrate salts mixture at different temperature, such as specific heat, thermal conductivity, density, dynamic viscosity and so on

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Abstract  

One of the greatest challenges in the application of organic phase change materials (PCMs) is to increase their thermal conductivity while maintaining high phase change enthalpy. 1-Tetradecanol/Ag nanowires composite PCM containing 62.73 wt% (about 11.8 vol%) of Ag nanowires showed remarkably high thermal conductivity (1.46 W m−1 K−1) and reasonably high phase change enthalpy (76.5 J g−1). This behavior was attributed to the high aspect ratio of Ag nanowires, few thermal conduct interfaces, and high interface thermal conductivity of Ag nanowires in the composite PCM. These results indicated that Ag nanowires might be strong candidates for thermal conductivity enhancement of organic PCMs.

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Abstract  

A BET thermodynamic model and its recently modified version were applied to predict the phase diagrams of the systems NH4NO3–LiNO3–H2O and NaNO3–LiNO3–Mg(NO3)2–H2O, in which two eutectic points were found with melting point at temperatures between 15 °C and 25 °C. Simple experiments were designed to measure the exothermal and endothermal behavior of the predicted phase change materials. The experimental results showed that the theoretically predicted materials possess excellent exothermal and endothermal behavior at room temperatures. Besides, the fusion and solidification heats of the predicted phase change materials were measured.

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Abstract  

This article is dedicated to develop an experimental approach for directly visualizing the global freezing phase change behavior of micro liquid droplets. The infrared (IR) thermograph was proposed to image the basic solidification phenomena of droplet and to acquire its temperature variations during the transient process. In particular, the volumetric recalescence event, regarded as initiation of freezing, was revealed by IR images for the first time. Preliminary results demonstrated that the involved temperature transition due to release of the latent heat can be accurately characterized by evident color break in IR images. Further, experiments were also performed simultaneously on three kinds of droplets made of pure water, dimethylsulfoxide (DMSO) and nano liquid to grasp more precise temporal and spatial temperature distribution. Types of the occurring solidification and the initial frozen volume produced from the recalescence were generally discussed. The IR monitoring method suggests a straightforward way for detecting the freezing phase change activity and its temperature evolution at micro scale.

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Abstract  

Supercooling suppression of microencapsulated n-tetradecane was measured using differential scanning calorimetry. Results indicate that the degree of supercooling is positively affected by the amount and type of nucleating agent present in bulk and microencapsulated n-tetradecane which it is used as a phase change material (MPCM). Results also demonstrate that the melting point of the n-tetradecane is fairly independent of nucleating agent concentration (0 – 4%). Conversely, the latent heat of fusion of n-tetradecane decreases considerably with nucleating agent amount and the initiation of crystallization point is inversely proportional to cooling rate.

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